load images in sequence into a gui?

You can make it easy and name the files like "name001.jpg", "name002.jpg"..."name600.jpg" and maybe do something like this:

 var imgNumber = 1;
 
 function Update()
 {
 
 loadAndSetTexture "name"+imgNumber;

 yield loadAndSetTexture;
 imgNumber + 1;

 }

Note that you'll have to create coad to load the img and set is as texture, i'm not on my computer so can't do that code for you. But you can use WWW for it. Like WWW "file:///the/local/path"+imgNumber. Prettey simple.

Yeah ok its a good idea but I/we found also an other solution: http://forum.unity3d.com/threads/90034-load-folder-into-texture2D-array

But your idea is also good. Thanks