Use a proper transfer switch. The avfrog and dryer plug version could shock a worker upstream from your house trying to repair the lines that caused the outage in the first place if you forget to open the main breaker.

 

Rockpick,
Doing it that way will work, but one mistake by you or the wife could injure/kill someone.
The transfer switch is the way to go. Or equally effective is the Interlock Kit mentioned before. These are slick as can be. You can learn about them here. No I do not owrk for them or sell them, but I have inspected the installation of them quite a bit. That's what I do for a living.

 

The way we used to do it is simple have 6 gauge wire with the appropriate male plug to correspond with any 220v female plug on inside of house( e.g. dryer). Turn off the main breaker to prevent back feed into the main line. With a big enough generator it can run anything you want. Cheap man's way

 

It's almost impossible to put power back on the main line with a generator. If you do not turn off the main breaker and leave your house connected to the grid, the transformer that drops 12K to 240 will try to convert the 120/240 from your generator back to 12K and energize the grid. Unless the break is very close to your house, you will be trying to electrify the grid and will immediately trip or burn up your generator. The only danger to utility crews is if the break is right next to your house and you're running a generator with the house's main breaker closed, electrifying the line from your house to the telephone pole, but little farther.

I actually asked a Allegheny Lineman about this when they were repiaring the lines after an ice storm. The lineman said that the neutral (or ground) wasn't an issue either, and they treat the lines as if they are hot as a matter of survival. He had no issues with people running generators and did not believe that it would pose a safety issue to any repairmen.

 

Actually, you can feed power back into the grid with the proper circuitry. Many utilities not only allow it (for people who have solar grids and/or wind generators) but will credit your utility bill for it.

Tyson's lineman was correct about the way they work on power lines. They are always treated as hot and either take precautions for working them hot or shunt them to ground (I worked for an electric and irrigation utility for 32 years including a few months on both overhead and underground line crews and 30 years of providing warehouse support for those crews).