I pondered whether to post this under apps or accessories, because I'm writing about both! But anyways, i just picked up a wemo switch and motion controls and they're working pretty well!
In case you haven't heard, there is now an early beta wemo controller app in the play store, specially for the S3 (although other devices seem to be working as well). Apparently the full app will be available by summer!
The app has limited functionality at the moment (most notably, you can't set rules as of yet) but you can easily cook up recipes for the wemo switch through ifttt.com.
There have been a couple of hickups with the app, but for the most part, it's been pretty good at controlling the switch.
Thank you, Belkin, for finally letting us Android users have smart control over our electronics