Probably when we should have been working, we were tumbling.
A tumblelog is essentially a blog without the baggage. You set it up for free in seconds, then publish your links, images, movies, quotes, whatever. For me it comes into its own by serving as an RSS feed aggregator: you can publish your del.icio.us links into it, as well as your Flickr photostream and loads of other bits – then feed it all back out again.
Projectionist is reliably offered as the daddy of the tumblr, while Max Wheeler‘s Penguin Classics tumblr had many of us wishing we’d tried it first. For the record, here are mine (which switches between colour-riot and ultra-minimalist about every 5 days) and Si’s.