It was already mentioned that you can use the keyboard to navigate contextual and system-wide menus by typing the first letter(s) of the item name. This, I'd like to add, in Panther now also works for the "Save as" panel. And even the shortcuts from the finder's "Go" menu work, too.
So if I want to save a web page from Mozilla, I press option-S to bring up the "save as" dialog, type the name I want to use, press option-shift-H to go to my home directory, then tab twice to activate the finder section of the panel, then t-e-m, and press enter to save in the directory called "temp" (it takes three letters in this case because I also have a dirctory called "test" :)).
Nice, and long-awaited, I guess.

