Images, TVs and linking

How do I setup PhpThumb to work in modx?

Just look at my code above (the first response to your original question).  I don’t integrate it with MODx (I think you can with PHx, but I don’t).  I just add PHPThumb into the snippets folder (you can add it anywhere on your server...I just put it in the snippets folder to keep things organized).  But there is no snippet implementation into MODx.  So just look at the code that I provided above and you’ll see how to use it.  But don’t get hung up on thinking that it "integrates" into MODx...the way I use PHPThumb, it acts as a standalone program.

Check out DirectResize, it is a modx plug-in.
http://modxcms.com/DirectResize-1802.html