Lint - A tool from the programmers' days of olde. PHP Lint and JSLint (for Javascript) analyze your code looking for syntactical issues and potential security holes. They wont prevent you from making bugs, but they will keep the stupid little ones from getting through.

Cufon - Uses Javascript to replace any text on your page with a graphical equivalent in the font of your choice. This is a great alternative to making static images for your text (a pain when the text has to change). See the text on davidmichaelross.com for an example of this library at work.

And, as always, great conversation with a group of friendly, knowledgeable developers and designers!