Or you can try Alpari, I think they let you do literally pennies per pip for forex.
For futures, the minimum is effectively a lot higher. Assume you trade ES - even with a very tight stop, such as two points, one contract will entail a risk of $100, plus commissions (about $5 or a little less with some brokers).
It depends, but if you are looking to try things out a spread betting company is probably best. Of course, there might be some fun and games to contend with along the way.