Co-GMs can be really helpful ^^ At the moment, I have two pals who help me out with my RP. They usually take care of things when I'm away, help with the scene setups, play important NPCs with me, and help out with the plotting. Their help has definitely been invaluable :D. It helps that we've known each other for a long time. If you're gonna get a co-GM, knowing them beforehand is a good idea. Kaga's idea works well too. Don't just pick the person who wants to be co-GM off the bat, pick someone you know you can plan with, someone who's dedicated to the RP and reliable. It helps when there's some level of trust and friendship there ^^