Transcend Digital Album is good choice for you to share and cherish your photos and mp3. And one good thing is that its lithium-ion battery is replaceable, convenient for user.
For its spec part, 20GB capacity, just one choice. 6V/2A AC Adapte, Li-ion rechargeable battery(2200mAH), 231g weight, 111.4 mm x 83.7 mm x 24.5 mm size, not so big.