U.S.A. Today offers up an interesting read on search guru Danny Sullivan. Oddly (somewhat out of context) on the left column was this tip for adding tags to social bookmarking sites. It is odd tagging would be mentioned anywhere on the page as Danny Sullivan is not a fan of tagging at all!
"Descriptive title "tags." Instead of calling a Web page, "Law offices of Mike Smith," write something more likely to be found, such as: "Seattle patent attorney Mike Smith," says Rand Fishkin, CEO of consultant SEOmoz.org.
Clean URLs. Instead of gibberish such as "www.patentlawyer.com/%20=30.html," use words that are likely to be understood, such as www.patentlawyer.com/mikesmith.html.
Lots of links. When people talk about your site or link to it you will be rewarded, Fishkin says. Links are easier to get than most people realize. The hypothetical lawyer could join groups such as attorney associations or the Better Business Bureau all of which offer links."
Well done! I am an absolute advocate of using tags smartly. The major engines are weighting tagged sites more often. We push tagging and show our clients how to push their site using them.