PSI/CO2 when out of town?

Just wanted to know what most people do. I am new to kegging and wanted to know how to handle being out of town for several days. Do you just leave the gas on at serving PSI while gone or do you shut the gas off and then when you get back hit it with a little higher psi briefly. I guess what I am asking is how long will it stay carbonated with the gas turned off in the fridge?
And upon returning home, what's the best way to make sure the first pour is still carbonated.

thanks

As long as the system is leak free, it will stay carbonated indefinately..

I would leave it on... not sure why you would turn it off unless you were worried about a leak.

If I was going to be gone for less than a week I'd leave it on. Otherwise, increase to 30psi until you hear it stop hissing then shut off the CO2. Also disconnect your beer QD's. That way you can sleep well at night knowing no beer will be pouring out of your kegereator onto the floor.