Your nearest home improvement or hardware store is likely to offer tile cutting services. Lowe's and Home Depot are the two most common stores. Some stores do not offer this service due to lack of demand or too many customers using it for all of their tile cutting needs.
You should call your local store and ask to make sure it can cut the type of tile you have. Some stores may be able to cut ceramic tiles for you, but not stone. If you have granite or other stone tiles, they may require a technician that has a wet tile saw. Your local yellow pages can offer the number of tile store or shop in your area.
Specialty flooring stores often cut tiles to size for customers. A minimum purchase may be required for some tile cutting services, or you may be charged a set fee per tile. If you have a larger tile cutting project, you can find a general contractor or advertise on Craigslist for an experienced tile cutter in your area. Home improvement stores often limit the amount of tile they will cut for you, and you have to be there while they cut it, making it unrealistic to have more than a few tiles cut this way.