These applications are a great way to make some extra money and reach hundreds of people through facebook.
Gift App
Demo:
http://apps.facebook.com/giftarea/
$20
Hot or Not App
Demo:
http://apps.facebook.com/amihott/
$25
Jokes App
Demo:
http://apps.facebook.com/jokearea/
$25
Arcade App
Demo:
http://apps.facebook.com/arcadefunland/
$30
As far as ads go, I personally suggest signing up with Cubics.com and using their advertisments. Ads must be in IFRAME and not javascript (which is what adsense uses)
I can install the app for you or send you the files, database, and instructions.