Concierge is a bookmark assistant plug-in for Safari that offers a multi-function scratchpad, bookmark managing tool and history sorting in a drawer on the side of the browser window. The scatchpad sounds like the most interesting feature, as it allows users to organize URLs, email links, Address Book contacts and even links to files and folders; great for heavy surfers and researchers alike.
This latest version addresses a few bug fixes and brings Universal Binary super-powers to this shareware utility. Check out Concierge's product page
for a demo and quite a few more details on all you can do with this handy plug-in, and a license will run you $10.