The Panasonic DY-PS10 is a Wireless Pocket Server which, through the use of SD cards, allows you to wirelessly stream music from the device to your iPhone or iPod Touch.
The idea behind it is to allow those whose phone memory just isn't up to scratch allowing them to fill their iPhone's with more important things like photos and games, leaving the DY-PS10 to handle the music side of things. Memory is expandable and so gives you the option of how much you want to fork out for an SD card, and the battery on board will give you a pretty impressive 10-hours of playback. Of course whether your handset will be able to actually match 10-hours is of course another matter.
Its come out in Japan and will cost around £117, it can also happily chew on your MP3's, H.264 files and JPEG's allowing you to fill your pockets with as much media as you can carry.