2007/3/7, tlm tlm1905@gmail.com:
Hit a key and you get a command-line with completion with some halfway-intelligent choice for the desired path (minus the filename) already filled in, which disappears if one hits another key. Every texteditor worth its salt that I know of has this option.
Sorry for continuing this thread. Cmd-O, Cmd-Shift-G will give you a tab-completed textfield where you can type the path of the file to open. Works in any Mac app that uses the standard open file dialog. Not quite what you wanted (2 keyboard shortcuts vs 1 key), but close.