this seems a good place to keep my list of handy tools.

http://validator.w3.org/checklink
http://www.anybrowser.com/siteviewer.html
http://www.seochat.com/seo-tools/link-popularity
http://www.marketleap.com/publinkpop 
http://www.webmaster-toolkit.com/search-engine-simulator.shtml

Can anyone add to this list?