I really recommend that you forget dealing with gas station air compressors. Those things can dump some water into your tires along with the air. Plus, they have a lot of pressure making it hard to fill a small tire like one on a motorcycle, without putting more in than you wanted.
My recommendation is to buy a bicycle pump and just keep it at home to use to top off the tire. There are a million of these pumps around, they work well, last a long time, are light, take up little room and you will get a little exercise when you use it. You can get a hand pump or a foot pump and many come with air pressure gauges on the pump. I have tried several and the gauges seem to be pretty accurate.
If you have the room to store it and can deal with the additional cost, I recommend a floor pump where you push down on the handle to pressurize the tire. I bought one recently on sale from a bicycle shop, that came with an air pressure gauge at the bottom where you place your feet to stabilize the pump, for only $25. It works well for topping off my motorcycle and car tires. In fact I plan to use it this morning as most of my motorcycle tires seem to loose at least one pound of air pressure a week. So I adjust them every two weeks.