DayZipping is a site that strives to help you find fun and interesting things to do in your city, or one that you are visiting, based around the idea of a day trip. It is one part travel site & one part social connect to help you explore your surroundings. I think it is an interesting idea that goes beyond the TripAdvisor experience that is heavily focused around reviews of a specific place.
With DayZipping you are able to find things to do that other people have already enjoyed. The beauty is that people are most likely only going to add things that they had fun doing (vs. complaints often found in a traditional review).
For instance, I plugged in San Francisco and found this great little walk that one user had done during their trip. I like that the site allows you to tell others how long something took as well as the cost. A few years ago, during a flight home from Europe, I had a choice between a 4 hour layover in London (during the day) or a 10 hour layover. I decided on the 10 hour option because I wanted to venture into the city for a few hours, I figured I would be able to explore for 6-7 hours. I mostly meandered around downtown & enjoyed beautiful views from the London Eye. If I had something like DayZipping I would would have been able to plan a route with more specifics in mind.
DayZipping also allows you to connect with friends to share trips with one another. You can easily make this happen using the Facebook Connect option on the site or by searching your email contacts. The idea behind this is that you are likely to be interested in the same things your friends are doing, so why not make it easy to follow along & experience what they have done in a city.
I also found, in Savannah, the Bohemian Hotel using the site for a contest giving away two free nights for users who create a trip using DayZipping. This is a great idea because it will get more people involved with adding content to the site for the city, as the whole concept of DayZipping only works if people are adding to it.
Overall, I think this is a site to watch for future growth. It has a great concept and the more people who use it, the better it will be.