pretty much im in the same boat. i valet cars a few days a week, and running one block to the lot for each car, by the end of the day my knees are killing me.
I wanna be able to run to get back in shape, but its not in the cards, theres no way i will be able to run a few miles every day. and i dont have enough money to buy a bike. I would prolly be able to do an elliptical trainer, because thats also little to no impact, but i dont wanna have to up and go to the gym to exercise
EDIT: im about 6 ft. 200 lbs, not really much muscle