GoPlanit is a service for travelers to find things to do in places they've never been. It removes the need to buy travel books by automatically figuring out your itinerary based on budget, physical health, and how much free time you've got.
The automatic planning feature is only available in a handful of cities, but is quite similar to autofill in Apple's iTunes. Clicking the "plan it" button automatically drops in things to do, and if you don't like one of the picked items you can delete it and get it filled in with something else that's nearby.
It uses a recommendation engine based on rated items from other GoPlanit users and reviews from places like CitySearch, Yelp and local newspapers. The items are placed in your schedule based on hours of operation per business or attraction, and grouped together by location. You can tweak a bunch of sliders like how much "intensity" you want, and how much you're willing to spend and it will adjust accordingly. For someone who is out of shape or a physical fitness nut this control will let either party tweak it to the appropriate level.
The site comes with a companion iPhone application so you can get mobile access to the itineraries with the phone numbers and addresses. This also lets you change something on the fly, or see other items from GoPlanit's directory. You can dump your entire itinerary into Google Calendar too.
Where all of this has real potential to come together is when it can take the recommendations from past trips and put them toward future ones. In a perfect world this would mean you'd have more targeted things to do when you're visiting new places. A post-trip debriefing on what was good and bad is a good first step.