I use the Javascript libraries Prototype and Script.aculo.us a good deal in my projects, but there was one feature they didn't have between them - form validation. A quick google uncovered a super-simple solution to this problem written by an Australian - all you need to start is one Javascript file and one line of Javascript, then add one single DOM-compatible attribute to your input lines and it'll work right out of the box. The even better part is that extending and enhancing it is very easy, just add a CSS line or two to customize your error messages, etc, easy as pie.

Script.aculo.us is a wonderful library of Javascript functions for doing lots of buzzword-friendly snazzy effects. A recent schmancy JS trick is the catfish - a small, unintrusive advertisement that pops up at the bottom of the web page and can be closed without affecting the web page. Looking around I didn't see any existing code to do catfish effects with Script.aculo.us so I decided I'd have to fill the gap.