I remember AOL (circa version 3 or 4) doing this. If you saved one of these (maybe by normal means, or maybe only by poking through the local cache) they'd have

I remember AOL (circa version 3 or 4) doing this. If you saved one of these (maybe by normal means, or maybe only by poking through the local cache) they'd have an .art filename extension and be some proprietary format that wouldn't load in most image software.