Here is good advice. Find a home you like and can afford at todays rates. If you will be there short term (3-7 years), consider a 5 or 7 year ARM. If you expect to be there longer than 7 years, go with a 30 year fixed rate mortgage. Don't get caught up in day to day changes in rates. If $20 per month is going to put you over the edge, then you should be looking at a home that is more affordable.
If rates fall, you can refinance and lower your payment. If they rise, you'll be glad you bought when you did and didn't wait until rates got lower. It's really pretty simple.