This is just a quick post – but one I hope helps many people. It seems every time I return to regex, it is after not using it for 6+ months, and I have to separately look up code examples, find a tool to verify the somewhat dodgy regex I knock up, test it out in code to see if it verifies my input the way I intend it to… sound familiar? If so, your problems have now been solved. Check out http://www.gskinner.com/RegExr/ – a FANTASTIC online regex builder / tester / expression repository, all combined into one neat little interface.