Forget about trying to make things as small as possible, or trying to pack in as much functionality as you can. Get with the program people: slim is in! Walletex is jumping all over the thin phenomenon with their Wallet MP3 player, a DAP that is literally credit card sized.

They’re claiming that this would the world’s slimmest MP3 player, and I think I would have to believe them. It’ll apparently come with a built in USB 2.0 connector that will be used not only for loading up those tunes, but also for charging and as the audio jack (“normal” headphones need not apply, at least without an adapter).

Walletex will be offering a 128MB version on the low end, right up to a 2-gigger for people that need a little more. What’s more, they’re willing to customize the look to your tastes, perhaps slapping on some company insignias for you to use as promotional material. No word on pricing (other than it will be “competitive”), but the Wallet MP3 is due for market by June.