A friend of my husband's recently launched a new community-based site for travel called Trip Tie. Like other travel sites, you can plan your travel and there are a list of useful resources. However, the clever aspect of the site is that you can read and submit your own trip itinerary. You can vote on itineraries, and if the content has changed, you can edit other people's itineraries. Tags help you to navigate around the site, and there already some fun ideas in there - "Las Vegas for "Ladies" anyone? Or 25 Days in Japan.
Image: Trip Tie