I use regex a lot, it's extremly powerful when used correctly. That said, sometimes I get tired of refreshing my page multiple times before I get something to work right... Enter "Eclipse Regular Expression Tester"; I've been running this for a couple days now and I've been pretty happy with it. So in case you never thought of getting something like this like me, I wanted to put this out there as a recomendation.

Usage was very simple, paste your multi-line content in the bottom box and type your expression into the top box. What ever your regex expression would select ends up getting highlighted down below... Pretty slick and super simple. No need for frills here.

Eclipse Regular Expression Tester