Every once in a while you come across a product which solves many problems and does it well. What problems you ask? How do I easily back up my DS games and have them all available (and playable) in one location. Secondly, is there a way of doing this which requires little effort and no modding knowledge?
The R4 DS Card is the solution to these problems.

“R4 shown with Micro SD card inserted.”
From the outside, you can hardly tell this is anything special. Looking more like a memory card than a game, it is exactly the same size as a DS card. It accepts any size of Micro SD cards; mine being 2gb. As you can see, those micro SD cards are smaller than a nickel. It locks into place with a secure click.

“Size comparison of Micro SD card/Nickel and R4/DS game.”
So what exactly does this mystery card do? That is the amazing part.
It’s main use is to take any DS rom and make it playable on the DS. With an average rom size of 64mb, you can fit quite a few DS games onto a 2gb SD card. And yes, these roms are fully functional exact duplicates of DS games. Everything is the same minus the source where they are found.
Let’s first take a look at what the UI looks like. As seen below, the user interface is very clean and simple. There are only three options, I will discuss the two main options; Games and Media.

“The user interface as seen after boot up. Top and Bottom Screen.”
The first icon (oddly enough the one with the camera and movie clapper… must be a programming error) is for games. When selected, a directory appears, which we then select ‘roms’. Below is a list of playable roms on my SD card. There is about 20 on there now, but plenty of room for more!

“The list of backed up DS roms on my SD card.”
Simply select one and the appropriate game is loaded. Unfortunately, there is no way of getting to the R4 menu post game load. You will have to restart the DS to select a new game. As an example, I have shown New Super Mario Bros. loading and in game shots.

“New Super Mario Bros. loading screen.”

“New Super Mario Bros. rom in action!”
The second icon on the menu (ironically of a gamepad) is for your media player. Once loaded, a directory is visible–listing all directories and files on your SD card. Roms are listed, but cannot be played from this program. The only thing we should be concerned with is Music and Videos.
As you can see from the video menu, the clean UI begins to diminish. Many windows show up on the bottom screen, but fortunately you don’t have to do anything with them. Simply find your movie file and play. Videos will only play on the top screen and sound quality is very nice for the DS.

“A look at the video directory.”

“An episode of ‘The Simpsons’ playing on the top screen.”
Similarly, the music menu has multiple windows layered on top of each other on the bottom screen. Navigation is simple enough, just find the artist, album, and then song that you want to play. To end a song just hit the “X” on the window on the bottom screen. Sound quality through the DS speakers is once again quite nice. Nothing fancy, just your average, bare-bones Mp3 player.

“R4’s music player rocking out to some random tunes.”
The very best part about all of this is that there is no external software needed. You don’t need a synchronization program on your computer to copy certain file types over. Just drag and drop roms, video, and music onto your Micro SD card and plug ‘er in. It really is as easy as that.
Additionally, the R4 is capable of loading and playing a number of homebrew apps. I personally have Doom which takes advantage of wireless multiplayer and a NES emulator with a whole slew of NES games.
To find out where you can buy the R4, refer to its official website. R4DS.net
The website also has information on what media is accepted and other details not covered in this review.
The R4 is truly a milestone for DS homebrew. I think this leapfrogs it over the continuously dominant homebrew gorilla, the PSP. With its ease of use and variety of applications at a cheap price tag, I recommend this card to all DS owners.