http://notepad-plus.sourceforge.net/
There are a lot of notepad replacements out there, but this is my new fave. It's absolutely excellent for any kind of scripting or coding. It has syntax highlighting for a whole pile of languages, auto-selected once you save a file with the right extension. So if you open a php file, a java file, a css file and an html file, it knows what goes where. It also integrates very nicely into the explorer context/right-click menu, allowing you the option of open in notepad++ on almost any kind of file
