A feature that I've long waited for -- window focus that follows the mouse between terminal windows -- has finally been added (in a hidden manner) to the 10.3 Terminal application. From the Terminal, type:
defaults write com.apple.Terminal FocusFollowsMouse -string YESQuit and restart the Terminal and enjoy! Now if I only had window autoraise, I'd be in heaven!
Mac OS X Hints
http://hints.macworld.com/article.php?story=20031029203936659