Are there any sites to test the speed of your hosting? I know there are sites that will tell you why your site is slow, e.g. - YSlow, etc., but how about the speed of bandwidth you get from your hosting provider?
The Net tab of the Firebug console (remember to disable browser cache).
Resources view of the Web Developer Tools in Chrome/Opera.
We use WebPageTest and Gomez for server tuning, Fiddler if there are any hard to diagnose problems, then the rest for front-end experience testing.
Once you have the level of concurrency and page-views a day the Apache ab benchmark/stress test tool helps.