There seems to be a new pattern emerging in Drupal and I want to let you know that the Token module has joined the bandwagon with a "Token Starter Kit"
History of the Starter Kit in Drupal: Zen Theming
When the Zen project started it's goal was to be a really solid base HTML theme with tons of comments in the templates so that a new themer could take it, modify it, and end up with a great theme. Unfortunately, that second step of modifying it meant that people ran into all sorts of support issues that were hard to debug and they were in trouble when a new version of Zen came out - they weren't really running Zen any more.
How to use the Token Starter Kit
The Token Starter Kit is meant to be similarly easy for folks to use. The idea is that if you just open up the token module itself and start adding tokens then you are "hacking a contrib" (modifying it) and you will have to remember to make those changes again when you upgrade. Bad news. It's also not particularly simple to understand how the module works (it's got includes, and hooks, oh my!).
Enter the tokenSTARTER module. Just copy the tokenSTARTER .info and .module files to a new directory in your modules directory, rename them, and rename all the functions inside to match the filenames. This gives you a clean place to start adding in your own tokens. So, go for it. You'll see that it's quite simple and all you need are two hooks.
Documentation on Token API
There's also an API.txt file and README.txt file which explain how to write tokens in general. Lots of great advice in there.