Web service that makes/displays HTTP request/response (includes POST, TRACE, headers, etc)

For the opposite, a URL which stores what's POSTed to it: <a href="http://www.postbin.org/" rel="nofollow">http://www.postbin.org/</a><p>For example: <a href="http://www.postbin.org/zfzfg2" rel="nofollow">http://www.postbin.org/zfzfg2</a> (superhappydevhouse.com's pbwiki's webhooks point there)

If you're using Firefox, I might use Tamper Data before I fed a request through a web service somewhere else; if you're using IE, I might use Fiddler.

I want something like this where you can type in the request body.