https://www.cloudflare.com/
loudFlare is an automated CDN / content acceleration type service. It acts as a reverse proxy providing some sort of heuristic security scanning, logging of traffic, and an automatically configured CDN. $15 + $5/site/month.
http://www.yottaa.com/
Similar to CloudFlare but more expensive ($30/mth no ssl, $130/mth with ssl) it accelerates web sites through the use of CDN, js/css combining, etc.
