kieren_j: Speck is right, PCX files are compressed in all color bit depths, but I find that 24bit PCX files have very low compression, less than 20%, and I don't particularly like the way they're encoded (I studied the PCX file format and wrote my own loader for this format, so I know what I'm talking about )
Splat: I'd have to say BMP files are the easiest to load, hehe! I looked into TGA file format a few months back, and it didn't look that easy. It only uses RLE compression, but the file header is quite a beast. You can cram a whole lot of stuff into that header, I'm beginning to wonder what the origin of that file format was.. looks like it was meant for images used in business apps, because you can have author's name, comments, charts, sales data, memos, phone numbers, la la la... just kidding
I'm looking at the PNG file format at www.w3.org (it's .org)... VERY interesting stuff. They stress the importance of ease of implementation on the developer's part, I'll find out how true that is when I go to implement it (yup, looks like I'm hooked on PNG for now).
If and when I finish my PNG library, I'll offer it up on these boards if anyone is interested.
Rappler: You're right, except you forgot to add the 54 byte header