Back in the old days of the Classic Mac OS (ah it seems so long ago now), there was an extension written called "ICeTEe" that allowed the user to command-click any URL in editable text in any application. ICeTEe would then open the URL for you; a clever and useful hack back then. What does this have to do with Mac OS X you might ask?
Nicholas Riley has cleverly updated ICeTEe for Mac OS X and renamed it "ICeCoffEE." This new version expands on the original and most significantly allows you to get to the "services" menu from the contextual menu (the menu that pops-up when you right- or control-click on some text). You can download it from his free software page.
I personally don't need the Command-click URL launching - but when I saw the services ability - I installed it immediately. Note that ICeCoffEE does not work in Carbon apps (such as the Finder) because it is implemented as an Input Manager.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20021022063820832