Switching Electricity Power Companies?

I'm new to the Houston area (Rosenberg) and had to choose a power company. I have a 3-month contract with Constellation for 10.2 cents per kWh as a new customer through the PowerToChoose website.

The renewal rate they're offering me is significantly more expensive, 50% higher!

1) What do people in Houston do to always have the best electric power rate?

2) Do you constantly jump from one power company to another, rate-shopping several times a year?

A lot of the power companies listed on the PowerToChoose website offer lower rates for "New Customers".

3) Am I a new customer if I still live at the same address and switch to a power company I haven't used before?

There are power company rate switching services that will automatically find the best cost and switch you automatically for a service fee. Takes all the searching and comparing and signing-up out of my hands.

4) Are power company rate switching services like "Energy Ogre" worth the service fee?

I'm moving in 6 months from Rosenberg to either Sugar Land or Katy.

5) If I'm in the middle of a power company contract, does it follow me to my new location or do I have to terminate the contract?

Just wondering what people do here to get the best rate.