Here's that snowflake tutorial I said I'd do. It teaches you how to create some rather realistic looking falling snowflakes in Flash. I used Flash CS4 here, but it should work w/ earlier versions too.
I threw this together really quickly so I don't know how clear the instructions are. It's also kinda hard to explain... but I hope you can figure out the steps >_< If not, just leave a comment and I'll try to answer your questions if it hasn't been answered already.
[link]
Again thanks! ^^
I haven't used gimp so I'm not sure. Conceptually it should work, but I dunno if you'll be able to make it loop in gimp.