If you need to save money and have younger children, forming a babysitting co-op can save a bundle. The savings can be from paying for a sitter for an evening out, or just having some alone shopping time. Find a group of parents whom you trust and trade babysitting services. Try to keep things equitable, if every member feels as though they are getting and giving the same amount things will work out better. You may even want to outline "The Rules" so that everyone knows and understands the guidelines.
Happy Child Free Evening!