I thought these free tools might be of interest since we need to start 
testing pound-2.0 beta.

Siege looks like a decent tool for hammering websites to simulate high 
loads:

http://www.joedog.org/siege/
http://packages.debian.org/unstable/web/siege

'Siege is an http regression testing and benchmarking utility. It was 
designed to let web developers measure the performance of their code 
under duress, to see how it will stand up to load on the internet. Siege 
supports basic authentication, cookies, HTTP and HTTPS protocols. It 
allows the user hit a web server with a configurable number of 
concurrent simulated users.'

WATIR looks like a decent browser-based (Internet Explorer) testing tool 
written in Ruby script.

http://wtr.rubyforge.org/

'WATIR stands for "Web Application Testing in Ruby". Watir is a free, 
open-source functional testing tool for automating browser-based tests 
of web applications. It is pronounced water.
Watir drives the Internet Explorer browser the same way people do. It 
clicks links, fills in forms, presses buttons. Watir also checks 
results, such as whether expected text appears on the page.'