Photoshop's scripting capabilities are pretty astonishing. I taught myself over lunch the other day. You can script in JavaScript, AppleScript, or VBScript and implement dialogs and UI panels.

It works exactly as you'd expect and scripts are quite lean (you don't need to do a bunch of setup).

I'm not an expert in Photoshop scripting by any means, so I'd have to remember how I did it first… in the meantime you can check out these tutorials:

http://www.kirupa.com/motiongraphics/ps_scripting.htm

http://morris-photographics.com/photoshop/tutorials/scriptin...