Fair warning, I'm kind of a sarcastic person, and most of my ideas tend to reflect that...
If you actually want to work on one of these, go for it! Just please let me know as I'd like to hear about it (and if you'd like, maybe help out where I can). Contact details in my profile page.
My three latest ideas with variations:
#1: Kitty cooker social game (please don't actually build this): Basically Cow Clicker meets prisoner's dilemma. Everyone gets a cute little kitten. In order to earn in-game currency (find a synonym for "cat poop" for a currency name, please), you must cook your friends' kittens. Your friends cannot cook your kitten if you have cooked theirs first. If all of your friends decide to abstain from kitten cooking for the day - you either all get gold, or all of your kitties get cooked anyway. In game currency can be used to buy cat clothes, cooking paraphernalia, recipes, etc. Recipes are a tradable item, effect earnings, might cost resources to use, and have a "cool down" period. Variant: Puppy kicker.
#2: A toolbox of satirical marriage help apps. I really don't have a lot of tool candidates, but they're easy to think up. For instance, "argument score keeper."
#3: Rent-a-sheep (name taken, needs something else): Presale of wool from individual New Zealand sheep. I live in New Zealand. There are lots of sheep here. Imagine a site where the landing page is a paddock of little fluffy sheep trotting around (SouthPark style animation, maybe?). When you click on a sheep, up pops a bio showing a photo of an actual sheep, from an actual farm in New Zealand. For a fee, you can "rent" this sheep, thereby receiving its wool production from that year. In the mean time, you'll get little auto-generated notifications about your sheep, perhaps including photos. You should also be able to choose how the wool is processed. That is, scouring, dying, spinning. All to be done in small batches.
Much easier variant: Small-batch customized supply chain for New Zealand yarn sold to yarn stores in the USA (aka create your store's own brand of yarn). Interface looks a bit like a slot machine - choose type of wool, then choose scourer/washer, then choose either/both dying service and spinning service.
Both variants should be very "connection" focused. That is, if you're renting a sheep, the site should do everything in its power to make you feel a connection with that sheep. If you're a yarn store owner, you should know a bit about the people who are performing each of the services, and you should hopefully have a window into how they're processing your yarn.