We r doing this. I heard about the 'Making Affordable Home Refinance Program' (thanks Obama). If your home is serviced by Freddie Mac or Fannie Mae, you should be able to refi without getting your home appraised. We are in the process of doing this now. Go to the website and read all the FAQ questions for details, they also have a part where you can see if your home is serviced by them (it's NOT the bank that you pay your mortgage to, that doesn't matter). From there, I called our Mortgage company our bank had a special # on their home page on the website for HARP) and sat on hold for over an hour (I work at my desk all day so I knew I could out-wait them). Keep telling them you are interested in HARP and want to refinance. Make sure you refer to, and look at the REFINANCE section, NOT the Home Affordable Modification program, that's for people who are behind on their mortgage already and will affect your credit negatively.
http://makinghomeaffordable.gov/
good luck