Today I came across a very simple tool for load-testing. It’s called AB and come with Apache HTTP Server. The command line arguments are very simple:
ab -n 10000 -c 10 http://your_web_site/url.html
Where -n is the number of successful requests and -c is the number of concurrence connections.
If you want to have more control over the URL you want to test, and much more, I recommend JMeter (also from Apache)