Re dating sites: Try OkCupid / POF. Or the up and comer LikaALot.
"Social recommendations", seriously are you insane? Do you have any idea how much business is driven via social recommendations? If social recommendations didn't work then amazon would have no 'people who bought, also bought...' If you had a company that could make those things 10% better you'd have a truckload of money.
Anything that makes programming "easy for non-programmers or businesspeople": You might want to ask a little company called Microsoft about that and how much money they make by making it easy to program. Perhaps you've heard of something called ruby / python, that offload massive amounts of intellectual capacity off of programmers. Seriously, how many ruby programmers know assembly? How many companies derive incredible amounts of money from things like profilers, etc. Barely, anyone programs computers anymore.
Anything involving paying people to look at ads: You might want to ask the hundreds of companies that run things called 'focus groups' about that.
Anything that promises to make email a thing of the past: You've probably got an IM client on your desktop, might want to ask 37 signals about a product called Campfire. There's also that company called Twitter.