To Paul, I used to do the tilt, lift and slide method (Leverage) with a previous rack I had but found that it wore out the back edges of the rack and the area of the vehicle where that was happening. If you want to continue that method, put a piece of heavy duty carpet between the rack and vehicle so it slides easier without scratching up.
This is where I got my ramp. Mine is a 5' it folds in half, locks with pins and has a carrying handle. Measure your slope and buy accordingly. Most places I go usually have a side ramp or raised pavement so the slope is gentle. Once in awhile I have to put the end directly on the ground but it is not too hard to get out the gear. I love it.
http://www.discountramps.com/handicap_ramp.htm