UserTesting.com is fast, cheap, quick and dirty testing - and that's a very good thing! You can commission one or more 15 minute tests specifying the demographic profile of your target audience, how many users you want, and what tasks you want them to perform on your site. The deliverable is a screen recording with think-aloud audio which is typically ready for viewing in 24 hours or less.
I heard about this via Steve Krug's e-newsletter, who passed along this fantastic deal: "until the end of May they're letting people buy pre-paid test credits at the old price, which are good for a year. If you haven't tried it yet, do it now (they have a 30-day money back guarantee) so that if you like it you can stock up on some credits while there's still time." If Steve Krug recommended it, you know it's good. Thanks Steve!