I have the eXo mini-bluetooth keyboard. It's rechargable and even has a laser pointer built in and a touchpad. Got it from here Amazon.com: eXo Keyboard: Computers & Accessories
(ticks me off, it's $10US cheaper than when I got it, LOL)
This works like a charm, although being so small, thumb typing on it takes getting used to. With the touchpad and Fn keys it's a Godsend. I use it with the Citrix Receiver app to access my company infrastructure and the soft keyboard is a bit, ummm, undeveloped on that app.
I connect to projector to run PPT presentations. Last one I was at, there were 3 of us doing presentations. The first two brought their laptops, I didn't. When they were done and my turn came, my boss asked if I needed time to get my laptop and set it up. Just smiled, took N7 out of my jacket pocket (already to go), set the projector to wireless receive, connected with N7 and started the PPT. Using this keyboard's laser I got through my presentation with flying colors, no glitches at all, N7 receiving bluetooth signals from the keyboard and sending wireless signals to the projector.
Afterwards my boss congratulated me on the PPT's "perfect timing". She saw my puzzeled look and said the screens on the presentation were so perfectly timed, they seemed to switch on their own. She didn't even know I had a keyboard, thought this thing was just a laser pointer. LOL
Anyway, loving it. No regrets, no problems. And recharges with standard mini USB.