Yesterday Facebook accepted my application ScienceHack into the applications directory. So far, its been a huge success, I am getting great exposure to my target audience and every time someone adds my application, many more come through the friends feed feature. If you have a start up dont hesitate to integrate it into Facebook.
I suppose if it isn't too much work, why not. While you are at it, also write some widgets for OS X, Google and Yahoo?
However, this is the third link today that leads me to the facebook login page. That sucks. Why do you have to login to see the available applications? I don't have a facebook account, so, whatever...
What are your thoughts?