Saw a TV ad last night for AC Pro, a simple one can R134A system that has the quick connector and a pressure indication to show status. Trigger operated, pretty simple, but you pay for the convenience - about $40 at the auto box stores on average. Or one of your local tire/service centers like Firestone, Goodyear, or any independent garage can check your pressure pretty cheap, and then top it off if it's low on refrigerant if you don't want to buy the hose.