As the site's author, Adam Seever of The Wantrepreneur, writes, "Your friends' online content provides clues about their interests. We can mine those text streams and suggest gifts for them."
First, define what you think your friend likes...
The service, in its alpha stage, is very simple. First provide the recipient's gender, what you believe they are into, and the price bracket, and then provide their social media accounts. Potential entries are Facebook, Twitter, FriendFeed, and a blog or other online profile.
Second, point to their online profiles...
Hit "Find Gifts", and Semantic Gifts, in the background, returns recommendations.
In my testing, using friends like Cyndy Aleo-Carreira, Jesse Stay, Kevin Fox and Robert Scoble, I found the site to be weighted toward offerings from Think Geek (which may say something about me and my friends), but also saw offerings from Urban Outfitters, Toys R Us, and others.
You're provided with three options, and can click "More please" to refresh and get three more. If you are completely at a loss as to what to get your friends this holiday, give Semantic Gifts a trial run. You just might be surprised. And if you think there are no good matches you want to buy, just get something for yourself instead.