Antonio Lupetti of Woorkup.com has created and released an awesome visual cheat sheet for WordPress 2.8. The cheat sheet contains a practical reference guide to 2.8 with references to WP Template Tags as well as sample code. Definitely worthy of being added to your resources bin.
Check out the live demo before you download the guide.
This is a pretty handy cheat sheet. Although it’s going to be potentially less useful depending on what theme you might be using.