I really like fences and it really helps to keep the desktop tidy. However, what I'd really love to see is the ability to collapse a fence into a single stack of icons. It was a cool feature in BumpTop (a desktop replacement app) until Google bought it and it stopped to be available. 

The reason I think it would be useful is that I'm one of these people who keep an awful lot of icons on the desktop - often more than there is space. For example, I tend to keep tens of TXT files with some notes. Currently Fences can just put a fence around them - which is a lot tidier but still all of them are displayed all of the time. I can also make the fence smaller but then it becomes necessary to scroll through them. The idea is to just have them in a pile and be able to fan the files out by a mouse over or something.

Here's a demo of bumptop (it's not available anymore so i think it's ok to post it). Of course all the 3D stuff etc. is an entirely different story, but the stacking feature really boosts productivity (the feature is demonstrated about 00:52) and something like that would be super cool in Fences.

http://www.youtube.com/watch?v=eqcmPJ-oVL0

Disclaimer: Of course some might say the same can be accomplished simply by creating a folder on the desktop and throwing the files there. Yet, for some reason this does not feel right. It's like saying that Fences could be replaced by creating folders, which is far from truth.