StealthRider: i think you were thinking "FTP" where he typed "SFTP". SFTP is a completely different protocol than FTP - it's part of SSH. What you're suggesting isn't going to work, unless you've got some sort of SFTP system extension that I don't know about (and if that's true,
please tell me because I want it!).
smllpx: I don't believe this is possible. There is a linux project that's working on an SSH file mount (it's called shfs or sshfs, something like that); but 1) it's kinda buggy cuz it's pre-alpha and 2) it's probably not gonna work with OS X anyway. If I remember correctly it required you to compile a kernel module (on Linux) for it to work.
Fugu is probably the closest thing available. It gives you a GUI front end to SFTP and SCP.
http://rsug.itd.umich.edu/software/fugu/