At Shawnee we just fill out a form asking name/phone number/drivers license/tail number so we can keep track of who/what/when. Usually gets fueled up by the pilots and I haven't had to fill it up myself in the time I've worked here. It's been used overnight a few times on some occasions if the pilots were nice and the airport was slow and they were coming back tomorrow early.
I have given pilots and passengers rides in my car when they needed it, one to a rodeo across from the airport, another to a guy who left his truck at a different place in town, and even a guy to an airport for a part about 30-45 away. Most have been incredibly grateful, one guy rode in (just him) on a PC-12 after hours and thought I was his chauffeur (I was working late and was just closing when I heard him enter the pattern). Turns out dispatch dropped the ball and he needed a ride to the casino so I loaded his stuff in and drove about 30 mins there. Did not seem that grateful at all.