Wow did I run across a useful tool today. Live HTTP Headers is an add on for Firefox. It shows the actual HTTP headers for each browser request you make. This is very useful for a lot of stuff, but especially for working on RESTful web services.
Why didn't I find this 2 weeks ago! lol.
Get the add on here: https://addons.mozilla.org/en-US/firefox/addon/3829/
Web Site for the Add On: http://livehttpheaders.mozdev.org/