A Saturday in early January, playing a few consecutive games as a Demoman on the Shack servers to try to get a feel for it (especially using the stickies). Turns out that even an "apprentice Demoman" can make some cool stuff happen, either through luck or just because explosions are neat. Here's some of the high points of my afternoon...
P.S. If you see party hats and balloons, don't be alarmed. Yes "party mode" was enabled on one of the servers. If you haven't seen this before: it's purely cosmetic; doesn't affect gameplay.