We have a web application that is sufficiently complicated that it's hard to accurately simulate production load.
One of our coping mechanisms has been to make sure that the hardware in the test environment is always slower that our production hardware, so load and performance problems will be more pronounced.
Are other folks out there doing this, what other strategies are you using?
I have a 7-year-old 600mHz Celeron laptop with 256MB RAM that I keep around for performance profiling. For testing network latency, you could get a delay proxy (or write one trivially); it gets a packet, waits X milliseconds, then passes it on.
Fiddler can help you test low-bandwidth -- can simulate latency of slower networks.
Hook up testmaker. Do some manual tests and let their proxy write the test script by recording what you did manually. Automate using the script(s). http://www.pushtotest.com/ Open source and free.