LinkedIn is an app for the iPhone, iPad and iPhone that lets you network with co-workers and other business professionals on the go.

If you're job searching in this economy, you know just how important networking with the right individuals can be. You're going to want to keep in touch with former colleagues, as well as be introduced to new ones. That's where LinkedIn can potentially give you some guidance.

In some ways it makes sense to think of LinkedIn as a hybrid of Twitter and Facebook for business professionals. Just like on Facebook, you friend people with whom you've previously worked or gone to school. You can hold conversations with them and also meet new people through their connections. LinkedIn is also like Twitter (and can actually be integrated with the site quite easily) in that you can post little status snippets in a few simple clicks.

What makes LinkedIn unique is that it's entirely focused on networking for business purposes. Former co-workers or supervisors can give you evaluations and recommendations, for one. You can also post your entire resume and job goals either publicly or to be viewed only by your current connections. LinkedIn requests that you know the person in some way before requesting to connect to them, but it's entirely optional.

This mobile version is a great compliment to LinkedIn's web app. You can respond to add requests, update your status and more, all from the comfort of your mobile device, wherever you happen to be.

LinkedIn is a truly useful resource for job seekers or those just interested in keeping in touch with work colleagues online.