Free Fault Injection Test Tools

WebScarab (HTTPush, Exodus)
Paros Proxy
Burp Spider
Burp Proxy
SPIKE Proxy
SPIKE
Achilles Proxy
Odysseus Proxy
Webstretch Proxy
Absinthe
NGS SQL Injection Inference Tool
Sensepost Wikto (Google cached fault-finding)
Foundstone Sitedigger (Google cached fault-finding)
Athena (SnakeLabs)