Never heard of one. Evo users always flaunt their stand like it's a big deal. Never seen the need for one.
The main use I see for the stand that Evo users use it (or any phone with a stand for that matter) for is for playing movies and music. (This is why I have an HP touchpad).
I actually went to breakfast with a friend today that has a Windows Phone 7 on T-Mobile with a stand and tried to start watching netflix.
I then started laughing at him because he couldn't get service and I said hold on let me turn on my "4g". Turned 4G on, got connected and then I said "Oh wait.. I cancelled netflix 3 months ago."
Moral of the story: It's useless. And there is only 1 camera on the phone and it's on the back. So I guess you could DIY a stand for the camera but honestly I just don't find it very practical or see a high demand for it.
Don't let me stop you from googling it further or creating a DIY tutorial though. Never really cared for this feature on my phone. More important than a stand to me is that lovely hardware keyboard.