The Business2WWW service offers to check out your Web site for you. And I mean check out. Over 5000 tests per page, done at a rate of 150 per minute. Things like load times, broken links et al.
Haven’t had a chance to check them out yet, but it looks interesting nonetheless. There’s a free summary test (requires registration) and then you pay from �175.00 for a small site with around 50 pages. This apparently nets you 15,000 tests (where am I going to put them all, ma?).