- Trial shareware through a deposit: send a deposit to a software developer to download their shareware. After the evaluation time elapses, be given an option to release the deposit or cancel the service and have the money returned. I don't know about you, but I would be far more likely to click "buy" to make a payment than to log in to a website, enter my home address and credit card info, pay a transaction fee, and wait for a registration key (or even use PayPal).
- Contribute to a project, but only pay after the project has been fully funded: imagine a scenario where someone is trying to raise money to produce a movie and they're soliciting contributions. Build a Bitcoin contract such that the funds aren't released until the total amount has been raised; otherwise, your money is returned to you. No lawyers, no paperwork, no fees.
- Create a dominance assurance contract: if the contact fails because not enough people have contributed after a certain period of time, those who contributed have their money returned and are paid an additional fee. This makes taking part to be always the correct strategy.
- Integrate a mediator into a transaction: should the two sides not agree that the contract was fulfilled (i.e., only one side of the contract was signed), the mediator can sign the contract to release payment to the side they agree with.
- Tie an external factor to a transaction: when the external factor evaluates true, payment is released. Example: pull a box score from a sports website. If a certain team has scored more goals and the game is over, the contract will release payment to the person who bet on the correct team.
Most of these ideas were pulled from https://en.bitcoin.it/wiki/Contracts. Have a look for yourself and see what else you can come up with!