[Greg Jones]

I use, and highly recommend, FastScripts myself but it is possible to assign shortcuts to scripts using the Keyboard & Mouse preferences. If one enables the 'Show Scripts menu in menu bar' option in the AppleScript Utility, then those menu items (scripts) can be assigned a shortcut with Keyboard & Mouse.

Also, in addition to FastScripts any utility such as LanuchBar, Quicksilver, Butler, QuicKeys, etc., can assign a trigger to a script. I believe every Mac user really should have one, or more, of the above-mentioned utilities.