IF you are looking for just a small amount of power - for an outage lasting a short time, or enough time to finish a movie or finish working on a document on your computer, you can get a Battery Back-Up at Sustain Ability. See
http://www.sustainabilitynh.com/prod...-back-up-power
The largest model has a run time of 70 minutes, with 450 watts of power, and phone and cable modem surge protection built in. $110. A smaller battery back-up unit provides 15 minutes of power and costs just $54.
I know this isn't in the range of running your clothes dryer... but if you just want to assure you don't lose data, or can finish a few tasks before shutting down and losing power, these can be very helpful.