[TxMt] editing the ctrl-click / right click context menu?

Is it possible to add entries to or edit the menu that appears when one right clicks or control clicks in the text editing area of the TextMate window?

I'd like to see a "Look [highlighted word] Up in Dictionary" command like that found in Safari / TextEdit / Mail / etc under Tiger. I know that there is a TextMate (applescript) command mentioned on the wiki which can do something similar with a key equivalent, but I'm used to the consistent interface to do this across these other programs, and I'd love to have the same interface in TextMate.

Thanks!

-- Matt Anderson