GIF above originally posted by halgand_cc on 544x378webtv (archives, week of 07/13/2003 - 07/19/2003)
Back when we were debating the "internet surf clubs" on Rhizome.org (conclusion: the Rhizome regulars said it wasn't art and if it was, it was something they invented), a commenter traced the idea of group image/may-or-may-not-be-art blogs back to the earliest days of blogging, late '90s-early '00s, in France I think. I first noted the phenom with 544 x 378 (Web TV) (see above). Nasty Nets came three years later, and added the term "internet surfing club" (pissing off a generation of academic net artists).
Tumblr blogs are too many and diffuse to be pigeonholed but their communal features and broad participation make the '06-'09 surf clubs seem creaky (the latter have drastically slowed their posting pace, anyway).
Now dump.fm has taken the concept(s) and sped them up even more with the addition of a live chat feature. Putting images in chat has been around--Yahoo! had a feature where two chatters could work on the same drawing in real time, using paintbox controls--maybe it still does. Dump.fm allows image and GIF uploads to a single public chat screen (also webcam shots) and is simultaneously creating a tumblr-like blog archive for each chatter consisting of that uploaded content.
The changing speed of the discussion and image uploading is not for the old or weak of heart. Chat is hell for me due to an inability to express myself in thoughts under a paragraph. (Twitter is fine for one-liners but lousy for conversations.) With chat you have to mesh quickly with the "house vibe" and have no ego about losing your precious words and pictures quickly in a volatile stream.