ThisNext, a social shopping and recommendations company, released an iWant application for Facebook last week. The application is pretty simple - install it and list the things you want, and iWant will feature them on your profile page and broadcast them in your feeds to your friends.
The application can be used in two very different ways. In the first, a user can designate very specific things that s/he wants, include the price and pointers to where it can be purchased, and broadcast the want to his or her network. (Similar to Amazon's Wishlist)
In the second example, a user can indicate a general want and solicit recommendations from his or her network. The Mashable interview with ThisNext founder Gordon Gould suggests that this is how they want users to use iWant: