I have a ghost shrimp and amano shrimp in my tank. They are great! They scavange the bottom and crawl through the plants looking for food. They do a great job of helping to keep the tank clean!
The amano shrimp eats algae and the ghost shrimp eats all the leftover flake food that sinks to the bottom and sometimes he will eat algea too. I feed them shrimp pellets and algae wafers as a supplement as well.
I've heard that they will climb out of tanks if you dont have a full hood on them, but I've never seen mine even try to get out. They mostly stay on the bottom or in the plants. Sometimes they will run up the side of the tank to the top and grab a peice of flake food and pull it down to the bottom to eat it. But they dont really "swim".
I have them in with guppies, mollies, and a plecostomus. They all get along great. Once one of my guppies died and soon as the ghost shrimp found it he claimed it as his prize and drug the poor dead guppy all over the tank. He looked so happy with it I let him keep it for a day before removing it. He ate the tail and fins off it too.
I always worry when vaccuuming the gravel that I will suck them up. I always pay close attention when cleaning not to get close to them. They will usually run away from the vaccuum hose and hide anytime I'm doing any cleaning in the tank.
I'd recommend these little shrimp for anyone!