I was in hiking in the woods once with my buddy when we saw a bear up the trail charging us. I immediately got down on one knee and started lacing my shoes. My buddy asked, "What are you doing? That's not going to help you outrun a bear." To which I replied, "I don't need to outrun the bear, I just need to outrun you."

It's like that with bikes, really. Someone who steals bikes is just going to go around until he finds one that's easy and is worth something. Lock your wheels up and it's the bike next to you that's going to have to be carried home. I'd encourage your friends to not lock their wheels and park nice and close to your bike. Hell, tell them that cable locks are great around a frame. Then you can use a lighter u-lock.