The people who made Twitter want us to create backend user applications for their product and you can easily make money online with them. Having people like us create applications that require Twitter makes Twitter more useful to everyone. The more useful Twitter is, the more people depend on it, and the longer it will stick around. There’s a ton of potential out there for making Twitter work to your advantage. Think of what you’d like Twitter to do and how you can make it make you money.
Think of the websites and web service you use right now. Wouldn’t making them work with Twitter bring attention to your product, service or company? Definitely. Some ideas for backend Twitter applications you can create to bring Twitter users flocking to your door include:

• An interface with social bookmarking sites like Digg or Fark that brings a Twitter user updates in real time for new articles that match keywords they enter. • An application that tracks eBay sales for each user in real time, or that tracks items the user is watching to bid on.

• An application that tracks the URLs people post in their Twitter messages and posts the stats on a website. This could be marketable data for the Internet marketer looking to find out what would sell well to Twitter users, or what would be the next great Internet-based product.

• An application that integrates MySpace and Twitter.

• An application that mashes Google Maps and Twitter users to help you track where your followers are located.

• A melding of iTunes, Last.FM, Mog.com or other e-music services and Twitter, similar to NowPlaying.

• An application that meshes Twitter and sites like del.icio.us or mag.nol.ia.

• A MyBlogLog and Twitter mashup application.

• A Twitter-based dating service…