Images other than bitmaps

Is there any way to use images other than bitmaps? I need to use an image that has a transparent background, and I dont think that bitmaps support background transparency. If anyone knows how to use other images or how to make a background transparent on a bitmap please help.

Thanks

I asked a similar question a little while ago. Here’s the resulting thread: http://www.opengl.org/discussion_boards/ubb/Forum3/HTML/002198.html