I have been out five times with friends since I started Cambridge and I have sparkling water in a glass with a straw and ice cubes. I also treat myself to a can of coke zero. The only down side is since am the only sober one, I have to make sure everyone gets home safe and no one talks to anyone they shouldn't be talking to lol. It's been fun every single time and a good pro is that they wake up with hangovers, I wake up with a clear energetic head lol.
To be honest though I could happily live the rest of my life without booze.