+1  A: 

I have occasionally used the Regular Expression Labratory

John M
Thanks - that's the idea, but it seems buggy - for instance, it throws an error on a simple ".*"... I'd accept your answer otherwise.
fakeleft
Second the buggy comment! Also its very vauge on the Re syntax actually supported (perl, pcre, sed, awk etc. etc.)
James Anderson
+1  A: 
Sridhar Ratnakumar
Thanks, but the replace feature is a must. I have a komodo license (kudos!), but I'd prefer something stand-alone so it launches quicker, etc.
fakeleft
+2  A: 

If using the JavaScript regular expression engine is acceptable, there's a nice one written by Erik Arvidsson. It doesn't have the "Replace" features that Komodo IDE's Rx Toolkit has, but it's helpful for testing matches.

He wrote for use with Komodo Edit - I guess he didn't want to shell out for the IDE either. ;)

Disclosure: Sridhar and I work for ActiveState, so we tend to push Komodo IDE. If $295 is a barrier for you, just tell our sales folks that you're a friend of Sridhar from stackoverflow and they might be able to swing a deal for you. We'll take it out of his pay.

Update: More shilling if that's OK. There's a sale on till the end of October. $50 off!

troyt
As stated elsewhere, I need the replace feature, so the first link's no good. However, the second link has a comment with a link to a tool that will do the trick: http://osteele.com/tools/rework/#. Thanks!
fakeleft