TRAMP

I just discovered TRAMP ("Transparent Remote (file) Access, Multiple Protocol"), an extension for GNU Emacs which allows you to open and save remote files very easily. For example, to open a remote file, you'd do your normal C-x C-f and then prefix the remote filename with "/hostname:" or "/userid@hostname:". It will then prompt you for your password and retrieve the file behind the scenes via ssh. Saving is handled in a similar transparent fashion (your password is cached temporarily).

TRAMP comes installed with Aquamacs, a pretty nice version of Emacs for MacOS X (except for the fact that you have to uncheck "Display Buffers in Separate Frames" once in order to get it to act more like normal Emacs). GNU Emacs on Redhat 9 comes with ange-ftp, which is similar to TRAMP, but only supports transfers via ftp.