Daring Fireball has a nice little step-by-step on how to create a system-wide word count feature in OS X using Apple Script and an app called, ThisService, from Waffle Software.
Don’t be intimidated by the words, Apple Script. The whole tutorial is only about 3 steps, and John gives you the script to copy/paste, so it’s real easy.
ThisService is an app for adding custom items to the Services menu found in OS X (10.4 only???), and it’s free, although donations are welcome. While you’re there, check out Waffle’s, Hex Color Picker. It allows you to add an extra tab in the system-wide color panel, so you can instantly see the hex color code for any color.
Hex Color Picker is one of those little things that make my web development life so much easier. Having the magnifying glass available for snatching color from any location on the screen, combined with the immediate identification of the hex value of that color is just dreamy.
I can’t remember whether you covered it here, but you can make the Color Picker into an app that can be opened up anytime using this hint from MacOSXHints:
http://www.macosxhints.com/article.php?story=20060408050920158&lsrc=osxh
Add the two-keystroke power of Quicksilver and snatching colors from anything on the screen is a snap. I use this all the time. I also use the control-scroll zooming in Tiger to get more accurate colors from small areas on the screen when using the magnifying glass feature of color picker.