There are many reasons why someone would want to hack the Nintendo DS. Most are legitimate - listen to MP3's, read ebooks, view photos, play homebrew games and watch videos. Of course there is also the illegal reason - to play ripped DS and Game Boy Advance games. I can't discuss the latter in too much detail here for fear of being sued. I can say that almost every game for the DS or GBA can be found online (as ROM files) if you know where to look. Keep in mind that this is illegal and you could download a game file that is actually a virus (which could turn your DS into a useless brick).
Most DS hacks involve the user having to open the system to short a contact point on the circuit board to override the DS firmware. This has many risks involved including personal injury (the power has to be plugged in when you do this), voiding your warranty or turning your DS into a brick (see above). I recommend staying away from this method unless you are very skilled with electronics.
I chose the plug and play method. This is the easiest way I found to hack the DS, and involves only three components:
1. PassCard 3
The PassCard3 fits right in the top of your DS like a normal game. When connected, this bypasses the DS firmware but does not erase it.

PassCard 3
2. M3 Game Boy Advance Movie Player
The M3 GBA Movie Player is where the flash media connects. You can chose the player depending on the type of flash media you want to use. I picked up the Mini SD model as it is the exact size as a GBA game. The regular SD and Compact Flash models stick out of the DS Lite much further. The GBA Movie Player also comes with the software required to get your content onto the flash card and play it on the DS.

DS Lite with GBA Movie Player connected
3. Flash media
The flash media holds the GBA Movie Player software and your content. If you plan on watching videos and listening to MP3's I would suggest getting at least a 1GB card. You will also need a card reader (for the type of card you chose) connected to your computer.
It's a very simple process to get up and running once you have all your hardware in place:
1. Install the software that came with the GBA Movie Player onto your Windows PC (Mac version coming soon).
2. Connect the flash card to your computer.
3. Convert and transfer your content to the flash card.
After you connect everything to the DS and turn it on you will notice a new splash screen and menu (see photos below). The menu now has folders for music, books, pictures, games and movies. Select what you want and enjoy!

New splash screen

New menu
Where to Buy?
There are many places on the Internet to purchase these devices. I picked mine up at GamerSection.ca as a bundle. GamerSection.ca has a great reputation, excellent customer service and I personally recommend them.
Needless to say I have been very happy with my hacked DS. Playing the occasional homebrew game (such as Drug Wars) is fun but I really enjoy the ability to read ebooks and watch videos on the go.
Check out these links for more information:
Nintendo DS homebrew
DS Wiki
M3 Adapter Forum
GamerSection.ca
M3 Adapter
Hacking the Nintendo DS flickr set
commandN Episode 58
Hey Brian, someone left a comment on Destructoid, they were wondering what the Passcard was for. They said, they had a movie player and it did the same thing. Thanks, again.
Posted by: Walter Crespo | August 24, 2006 at 10:04 PM
The movie player on its own will play videos, ebooks, MP3s, photos, etc. but will only play GBA home brew games/roms.
The Passcard is needed to play DS home brew and roms.
-Brian
Posted by: Brian McKechnie | August 25, 2006 at 10:22 AM
Hey Brian,
I found this on my websearch for media players and am wondering if you've heard anything about it. My main interest in it is that when it's inserted it flush with the unit and well I'm a girlie girl so these things are important :)
http://www.jandaman.com/games.mvc?p=ndsscsdl&Category_code=NDSDEVKIT
Thanks
Kerri
Posted by: Kerri | September 01, 2006 at 10:05 PM
hey Brian i was wondering if this passcard3 system would work on the new black ds lites comming out in september.Nintendo might change the version of the firmware and im worried ill buy it and be screwed
Posted by: edwin | September 03, 2006 at 12:52 AM
Kerri,
I also prefer the one that is flush with the unit and might have to upgrade.
I don't know much about the brand you listed but M3 does make one also:
http://www.gamersection.ca/product_info.php?products_id=289&osCsid=hn4tor99937a46784r47bt54v2
Hope that helps.
-Brian
Posted by: Brian McKechnie | September 05, 2006 at 02:37 PM
Edwin,
Good question! I have asked around and no one has heard anything about a firmware upgrade.
The thing about using the Passcard3 is that it bypasses the firmware and does not erase/change it. Therefore if Nintendo did change the firmware, the Passcard3 would not hurt the unit and M3 would most likely send an update to keep it working.
The black Movie Player is now available to match the black DS so there is support for it.
If I hear anything I will post it.
-Brian
Posted by: Brian McKechnie | September 05, 2006 at 02:41 PM
When you are done witrh the PassCard 3 and shut the power off and the the card out, when you turn your DS back on does the normal menu appear? Also i am assuming this works with the DS Lite aswell?
Posted by: Bob | September 09, 2006 at 02:36 PM
Bob,
Yes, when the Passcard 3 is removed the normal DS menu appears.
This does work on both the DS and the DS Lite.
-Brian
Posted by: Brian McKechnie | September 09, 2006 at 02:48 PM
Brian,
Is the M3 perfect Lite available in black and is that the only thing you need to listen to music and watch videos on the DS?
Posted by: Josh | September 21, 2006 at 11:52 PM
Brian,
What does the supercard lite do? is this used to play music and movies on the DS
Posted by: Vanessa | September 22, 2006 at 09:33 PM
I don't quite understand what the Movie Player is for. Would it be possible to just use the Passcard 3?
Posted by: Ben | November 01, 2006 at 11:51 PM
Hi, I'm really interested in getting these things for the ds lite, but I googled around and found some answers and some more questions... wht about the x-treme card? could it be used instead of the passcard3, while still using the M3?
I also got confused with so many different devices out there, but in your experience, these two itesm that you bought, do they work with homebrew software and roms? [so I don't have to be carrying around all my games physically hehe] cuz that's all that matters to me actually, if it works, I don't mind the xtreme ot w/e. Thanks alot!!
Posted by: djin | December 16, 2006 at 02:16 PM
Are the prices at GamerSection.ca in Canadian dollars or American?
Posted by: Christian | February 10, 2007 at 01:19 PM
My question is this, i bought the bundle of gba movie player and passcard 3 plus a 1gig mini-sd, will i need anything else to connect those things to my pc?
Posted by: Ben | June 11, 2007 at 07:45 AM
Hi,
Is there a way to make software that can be uploaded on the DS lite so thst parents can set a play limit like for a couple of hours for 1 day. So that the kid can use up his minutes or hours in several blocks during the day. Thx Mike
Posted by: mike | September 01, 2007 at 01:34 AM
Hey guys.. I just started this website its www.freewebs.com/gamersege
Ithnk im the first one ev3r to name it i just got it a x-fire sever chat///// security sever that i made interested of working in my company? Well Contact me at redsmackdown@yahoo.com or redsmackdown@hotmail.com
Dont forget abou BLACK FRIDAY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!~↓~♪♪♪♪♪♪♪
Posted by: EGEGAMERDANIEL | November 19, 2007 at 10:33 PM
This was the worst write-up I've ever read. The author is affraid of being sued, as though he doesn't have 1st amendment writes. Grow up, you wussy.
Posted by: wasted my time | August 05, 2008 at 11:52 PM
Brian, if you get this bundle and hack your ds would you be able to take it out and play a normal game. would i get o keep my old splash screen. thanks
Posted by: NIkita | April 17, 2009 at 07:33 PM