I'm not a big fan of disposable batteries, or even rechargeable ones. i'm more interested in the GBA SP solution, where you can plug it directly into AC. However, it would be much more convenient for me to just plug it into a usb port. after some looking around, i can't find anything that would fit the bill. i'm ok with some DIY, as long as the full product can fit inside the original case and not stick out. anyone have any insights on where to start?