I had my right hip replaced in January 2009. I was back to work in 4 weeks, not driving, but commuting to my job in NYC via train and subway. Three months later I built a large shed in my yard. DW was yelling at me to be careful when I was up on the roof nailing the shingles. We took our first camping trip in May of that year with no problems.
The key to any joint replacement is an expert doctor and physical therapist working together. My left hip is starting to give me problems and I will not hesitate to get it replaced.
Everyone is different, so as others have said listen to your doctor. I found a great website for hip replacement information.
Surface Hippy