I just don't think in regular expressions like some people.  I don't use regular expressions often, but every time I need them I wish that I would just learn the syntax because I end up going through a ton of time in debug more trying out various expressions.  Since I haven't bitten the bullet and become a Regex guru, EricGu's Regular Expression Workbench (V2.00)  is the next best thing.  It saved me probably an hour last night with a complex expression.