I also am having a blast using my Logitech Wave wireless kit (K350 Wireless keyboard and M510 wireless mouse) with my Nexus 7.
I plugged the Logitech USB receiver to the OTG adapter on my Nexus 7 and boom!
No Root, no apps, no Bluetooth requirement.
It just works.
Even the Quick Keys on the keyboard like calculator, email, www actually opens the corresponding applications !
The Volume Up and Down keys as well as music buttons work too.
“CTRL A” – “CTRL C” – “CTRL V” do their thing…
USB wireless keyboards and mice work great with the Nexus 7 right out of the box !
PS1. original post here.
PS2. I bought my OTG cable for 0.99$ on eBay (from a US seller).