I recently StumbledUpon the article You Don’t Know Anything About Regular Expressions: A Complete Guide at Nettuts+. It’s geared towards using Perl-Compatible Regular Expressions (PCRE) in JavaScript, but is useful enough and accessibly written that many might benefit from checking it out. The tutorial starts off with the basic syntax and characters, but then runs through five videos showing their use in action. The rest of the tutorial, which is largely JavaScript code, outlines how you can parse email addresses and URI’s using regular expressions.