Tools for testing security of sites and services

SOAP UI (Free) (New Rest and Json support)
Send raw SOAP, XML, REST/JSON requests to services.

Soap Sonar (Free version available)
Offers a much better user experience than Soap UI.

PortSwigger (Free)
Send handcrafted HTTP requests + Proxy

Fiddler (Free)
Web Debugging Proxy

OpenSSL
Test supported SSL protocols.