The new WordPress 2.9 released today features a new functionality for WordPress theme designers/coders to add post thumbnails by using the command the_post_thumnail().

Of course, don’t forget that the fact that in order to use this feature, you need to select an image under WordPress admin area and click on “Use as thumbnail”.

I have tried using on older images but seems like it won’t work on the older images. I am sure there’s a way to hack it so the first image of any post will be used as default thumbnail. But I think I will stick with my custom-hack job, it’s already working, why fix it?

For those of you who want to try out the new features without breaking your old post thumbnail code, you can read this blog post, which details on how you can do that.

And also this one for more resources on the_post_thumbnail() function features.