Actually, a BMP can be just as small as a GIF, since both support RLE; the difference is that in practice, RLEing a GIF is the rule rather than the exception, while RLEing a BMP is the exception rather than the rule.
As of now, all spaces are replaced with underscores, and weird file extensions become spelled in versals. I haven't quite figured out why yet, but capitalized file extensions (.JPG) causes problems with image displayment, although they store just fine. But so far, the service is fully functional.
"Stephen Wolfram is the creator of Mathematica and is widely regarded as the most important innovator in scientific and technical computing today." - Stephen Wolfram