I don’t know that this title make you think off, but i couldn’t express better the subject. We’re talking about SD cards that are not what you’d expect them to be. Sparfun electronics accidentally discovered while looking inside an SD card that it actually contains a micro SD card soldered to the SD pins. The job looks like it is hand soldered so the guys from sparkfun think there must have been a huge batch of microSD cards and a perceived shortage of full size SD cards.
The Truth Behind SD Cards: [Link]
I say another, because we all know the DIY MP3 Player and the AVR Butterfly MP3 Player. This mp3 player can support up to 4 GB of storage (MMC or SD cards) runs from a single AAA battery and has full user control (volume, track, pause, skip, directory) with a 5-way micro joystick.
Also the LCD has contrast control, you can record voice and the firm-wire is totally upgradeable trough RS232. In fact this DIY MP3 player is the coolest I’ve seen so far and it’s full of tricks.
EchoMp3 Another DIY MP3 Player: [Link]