Actually in Xmas eve we prepared alpha preview of WEBO Site SpeedUp (formerly Web Optimizer). You can get it from official repository here (link updated to alpha2): http://code.google.com/p/web-optimizator/downloads/detail?name=webo.site.speedup.v0.9.1b.zip. Main feature is new interface and a few more tools + improved overall stability. Some screenshots:
Here are all important blocks which should help you to increase load speed of your website - Settings overview, System status, Cache, Load speed, optimization tools, Updates, News, etc.
On cache screen you can refresh overall cache and get all information about actual files.
On cache reload you see all performed actions.
Here are listed all warnings / troubles with server environment, also some useful information about application.
Optimization tools (static gzip and image optimization) allow you to compress your files in interactive mode. Image optimization will be performed via smush.it / punypng.com services (in alpha only former is available).
Get alpha2 version http://code.google.com/p/web-optimizator/downloads/detail?name=webo.site.speedup.v0.9.1b.zip and leave your feedback.
Any issues can be also submitted to issue tracker.