I found an interesting Safari bookmarks page on Apple's site. On this page, they provide some useful JavaScript bookmarks that can communicate with additional applications such as Sherloc.
Here's an alternative version to search webster for a word definition. Enter the following bookmark defintion as one line with no spaces at all between characters:
javascript:x=escape(getSelection());window.location=
'http://www.webster.com/cgi-bin/dictionary?book=dictionary&va='+x;
[robg adds: The submitted hint also included a JavaScript to search Google for the selected text, but it's somewhat redundant -- you can just control-click on any selected text and choose Google search. However, for completeness sake, here's the Google JavaScript:
javascript:x=escape(getSelection());window.location= 'http://www.google.com/search?q='+x;Again, enter it as one line without any spaces at all.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=2003071101423319