Maybe I'm spoiled - but then again, maybe I'm a power user. I don't think of an app that accumulates to 40MB as a large one. Not to sound flippant, just a question - how about using Microsoft's strategy - buy more RAM? I assume that 40MB is a peak, or do you see it get much larger over time? Mine takes up over 25MB on load, and I have 3 auto-hiding docks, 1 tabbed dock, and 1 always-showing (task bar) dock.
Ever since I upgraded to OD+, I was able to make a Sys Tray dock and get rid of my task bar, and I love it!