Glassdoor is a careers site that competes in the same realm as as CareerBuilder and Monster. They have recently integrated an interesting Facebook app that will reveal what personal connections you have for a job you are potentially hunting.
When you do a job hunt on Glassdoor, you can read reviews, see salary information and photos, etc. all provided by current and former employees of the company you are researching.
Now, with the Facebook integration, you can see what sort of connections you have with the company from within your Facebook friends that might give you an "in" for the job.