Ever since I was a boy, when I used to play Pokemon on my old Gameboy (Codenamed The 'Big grey brick') I really wanted all of the cool gadgets that Ash always had.
When the Television series showed on American television, I fell in love with the Pokedex. Since then I have always wanted to have one of my own. So lets get started on it!

Step 1: Materials

So, what should we use? We could build our own interface, salvage the screen from a dead digital camera, accumulate all of the data on the Pokemon. And this is a project that I am perusing in my spare time. But for our purposes, we can just keep it simple.

Component : a Nintendo DS. The DS provides us with most of what we need. It has a similar Form-factor: it opens like a Pokedex, it has a good screen we can use, buttons, and of course, we can use it to PLAY pokemon.

Component : R4i-SDHC. Onto this card, we can load anything we want, and make it play in the DS. You can Purchase one here:
http://www.r4ds-ds.com/products/R4i-SDHC-V1.4-Adaptor-with-Kingston-TF-4GB-Card-for-NDSi-NDSL-NDS-R4i-sdhc.com-p-169.html Cost: about $30
This may not be the cheapest, but it will work with all the DS versions (excepting the 3ds, which has not yet been tested with this)

Component : GeneriDex. This is a compilation of the PokeDex information in the games. (Props go to saviorkross for putting this together) you can find it here:
http://filetrip.net/g25123591-GeneriDex.html
This even has a few awesome features that savirokross has built in like a 'Name that Pokemon' and 'Name that Cry' function. He has been VERY thorough, and intends on updating the file in the next month or so with the newest info.

Future Project : As i have mentioned, i am working toward getting a PokeDex of my own compilation off the ground, and for my finished product, i am doing the coding myself. I really like the interfaces on websites like, so just to give you a taste of what lies ahead...
http://www.serebii.net/pokedex-dp/
and
http://pokebar.com/
(These guys happen to have a PokeDex toolbar too)

Step 2: The 'Dex'

Now that we have all of our components, we can load the GeneriDex onto our R4iSDHC. We do this by connecting the microSD card (usually through a normal SD adapter) to a computer, Formatting the card, and using the simple "Drag and Drop" method to put it on the card. Next, we put the microSD card into the R4iSDHC, and put that into our DS. Crank that up, and watch the magic happen.

For more information, R4I has very good instructions on youtube:
http://www.youtube.com/watch?v=Gu1FFgszcLs (Official video)

Step 3: Optional Customization

So, for those of us who are not satisfied with it just working like a PokeDex, we can make it look like one.

Break out the Red paint! Here are some renders/screenshots of the various PokeDex configurations. Now it is time to pick your favorite, and make them match. Obviously, we want to leave the full functionality of a DS intact, so lets focus on matching with the paint, rather than hacking apart our DS.

Step 4: The Future

Now we have a working PokeDex. For the version I am currently building, I am building it out of an old PokeDex toy that was made by Tiger Electronics several years ago.
I hope to add in a random feature, that will randomly display a Pokemon when I open it up, so it can feel more like i am encountering a Pokemon like in the television series. (Funny story, a there is a joke that a friend of mine made, that if I ever got this off the ground, pointing it at myself the PokeDex would surely identify me as Snorlax)
I Also plan on integrating an audio component, and would be very happy if i could get the audio from the Television Series, however i see that as very unlikely.
When I finally get that project finished, I will post it here, along with the code, so people can take it and run with it.
Cheers and enjoy your PokeDex/Nintendo DS.