Aww, snails are not necessarily a problem. If they're ramshorns or MTS, keep em, they're pretty cool. I'm not as sympathetic to pond snails, but still. A few aren't bad, as they eat up leftover food. Just don't feed too much, or you really will have a problem on your hands.
If you don't want them, you can just pick out the babies now and head off an infestation. You probably just had an egg clutch or two on the plants that have hatched. So if you act fast you can get them out before they reproduce. Some people recommend throwing in a bit of veggie and taking it out in the morning with all the snails still munching on it and tossing the whole thing.
Edit - aww, I got beat to the answer! I disagree that they will overrun your tank. I have snails in all 6 of my tanks, and the only one with a lot of them is the tank I use for actually breeding snails. Just watch how much food you throw in the tank. And honestly I think fish do help to control the population, at least for certain species. I have several little ramshorns in my community tank, and have never seen a baby one in there, to my dismay.