There's been a lot of news headlines about people making tons of money real quick developing small iPhone applications and then selling them for small amounts of money ($1-2 apiece). It's a great idea, and one that your company or organization can use to help spread the word about your products, or reach a target audience that can use the iPhone application that you develop.
It's not as simple to design and code an iPhone application as it is to design and develop a Web site but the benefit of making an iPhone app is that you can charge its users and actually make some direct money from its use.
Here's a few things to keep in mind when you are looking to develop and iPhone application:
Who is the audience and what would appeal to them?
Don't think too complex - the most popular iPhone applications are ones that are very simple and easy to use.
What would be something that your application users would need again and again - they'll be more likely to download and pay for an iPhone application from the Apple App Store if it is something they could picture themselves using a lot.
Think FUN - it doesn't have to be serious, it doesn't have to necessarily enrich people's lives. People want something a little unique that is fun and rewarding to use.