People already share photos, videos, and even website bookmarks -- so why not add travel plans to the list? TripHub is the latest venture-capital-backed startup to make a bet on adding social features to an established form of e-commerce, reports TechCrunch. Unlike online travel agents which just book flights, cars, and hotels for travelers, TripHub aims to manage group travel. The site hopes to replace mass emails with blogs, online itineraries, and other tools meant to simplify the logistics of getting a large number of people to arrive at the same place at the same time.

Alaska Airlines has already signed up to create an Alaska-branded version of TripHub, which suggests that the startup could end up making its money by providing travel-planning tools to other businesses rather than building a travel-destination website for consumers, which could require expensive marketing.

At GigaOm, Katie Fehrenbacher says that a recent 120-person family reunion she attended "sorely needed TripHub's help." But she's not as sanguine about TripHub's chances for success. Yahoo Travel, she points out, is already adding social features like trip blogs. And it would be a simple matter to integrate Yahoo Travel with Yahoo Groups to duplicate most of what TripHub does.