We're predicted to have temps in the single digits tomorrow.  That's 25 degrees less than it's been so far.  I've already wrapped my trees but this year I got some non-LED rope lights and strung them around the branches.  While shopping for the cloth backed tarps I saw a remote controlled outlet.  It's like a short extension cord with a keychain remote.  For $10 I decided to try it.  It works like a charm.  So at about 2 am, when it hits 15 degrees instead of going outside to plug in my tree warmers, I'll just reach over without getting out of bed and click.  Both me and my fig tree all snuggly and warm.

Cool Robert. Where did u find them? Pics?

Nice.

I use incandescent Xmas lights for freeze protection on tender outdoor plants as well. 
They work well for citrus in their first and second winter in-ground here. We get about
a dozen nights a year where the temp dips barely below freezing here in a typical
winter. 2 of the last 3 winters have been a lot colder than normal though. I used the
Xmas lights on my in-ground figs last year and will again this year, although I don't
know if it gets cold enough here to worry about figs. None of my figs, potted or in-ground
showed damage and last winter was really cold for here. Last winter was really hard on
the citrus though, even well established trees.

I use thermostat outlet splitters to run them. They come on at 35F and back off @ 45F.

 
http://www.amazon.com/Farm-Innovators-TC-3-Thermostatically-Controlled/dp/B0006U2HD2