'Carnivals' are blog round-ups about what's going on in the blogosphere and/or fields of related interest.
There is David Meadows with his daily classicarnival at the rogueclassicism blog. Some of you may know David from his Yahoo! Anthropology and Archaeology Group, The Explorator, with his weekly news roundups. As Phil Harland remarks in his blog, "How does he keep up with it all?"
There is also the Biblical Studies Carnival, and the general gateway History Carnival.
Having now 'kept up with it' too, I'll return to 'work' work myself …