Here's a trick I use to copy my ssh public key to my clipboard with a keyboard shortcut using Quicksilver on OS X.
Open Quicksilver preferences and choose "Trigger", then click "+" on the bottom of the screen to create a new trigger.
For the first pane, hit ".", then type the following text:
pbcopy < ~/.ssh/id_rsa.pub
For the second pane, choose "Run Command in Shell" as the action.
Choose a keyboard shortcut (I use Alt-P).