Run up the Walmart store and pick yourself up a $6 universal remote. Just make sure it lists "Roku" on the list of supported devices on the package. If it doesn't work right, take it back and get your money back.
For some reason, my wife had a Roku 2 XS (Bluetooth) remote in the same drawer with the Roku 3 (WiDi) remote, and the first time I thought the remote wouldn't pair is because I had the wrong remote! When I created this post, I didn't have any idea I was using the wrong remote! Oops!
I put new batteries in the Roku 3 remote, and MAGIC!
Physical differences in the two remotes include:
Roku 3 remote has a headphone jack and volume buttons on the side- Roku 2 XS button doesn't.
Roku 3 remote only has ONE light at the bottom of the front of the remote- Roku 2 XS has two.