What terminal emulator do you use ?
christefano: iTerm for OS X is fantastic. I like the custom keyboard profiles, full screen mode and appearance niceties (like tab styles and being able to hide the scrollbar). An especially great feature is the multiple tab input mode. Not too long ago I ssh'd into 3 new servers for three separate clients and did essentially the same setup and security updates for about an hour. At the end, I was able to bill for 3 hours.  http://iterm.sourceforge.net/

I also use Visor, a handy utility written by Nicholas Jitkoff (the creator of Quicksilver). It extends Apple's Terminal by giving it a heads-up display, making a terminal available in any program by simply hitting a keystroke. It doesn't work with Snow Leopard, though, and when I first upgraded I actually felt like one of my limbs was always asleep. Fortunately, there's a way to make it work:  http://metaskills.net/2009/8/18/visor-terminal-on-snow-leopard

For one-off commands where I don't need to see any output (like killing or renicing processes), I use Quicksilver in command mode and use the "run command in shell" action. The latest version of Quicksilver works with Snow Leopard with very minor problems:  http://code.google.com/p/blacktree-alchemy/downloads/list