http://webo.in/ — русский сервис, выдает советы по улучшению сайтов
http://zoompf.com/free
http://site-perf.com/
- HTTP-compression support
- Keep-Alive support
- Advanced on-the-fly HTML parsing
- HTTP-Authentication support
- Smart parallel downloads
- Tests from around the world
http://websiteoptimization.com/services/analyze/
http://tools.pingdom.com/
http://googlewebmastercentral.blogspot.com/2010/04/using-site-speed-in-web-search-ranking.html