Website stress-testing

How to complete website stress-testing project

[priidik]

I would like to outsource website stress-testing.
Do you know some good and simple service/software that can help?

Please sticky mail the url-s if you have real suggestions.

[trillianjedi]

Plenty of open-source applications out there for doing this:-

[google.com...]

[mhhfive]

any warnings or recommendations? Stuff to look out for? Like do these stress testers simulate ok.. but the reality doesn't match?