WordPress 2.9 built in new features, like Online Image editor and Post Thumbnail, On this post I will give some information about post that coverage Post Thumbnail, So, if you need to know about Post Thumbnail and add your theme support this featured you should Read on this post
- About WordPress Post Thumbnail
- Everything you need to know about WordPress 2.9’s post image feature
- Display post image with backward compatibility
- Using The New Post Thumbnail Feature In WordPress 2.9
- Post Thumbnails in RSS Feeds
- And Many More
Happy Explore new featured in WordPress 2.9 and have nice holiday 
I also written some tutorial how to fix TimThumb readfile problem