Facebook already allows me to hide the rare thing I don't want certain friends seeing, this seems overkill, although I'm assuming there is more to Frid.ge than just being able to hide from certain people so I won't say it's a terrible idea, but based on the video I am not attracted to it.
FB groups do not capture this reality, the groups that are created stay and information shared is always available even after an event, or group moves on.
I believe fridge is on to a more accurate social graph. Add business and commerce solutions and you got your self a relevant business model.
Businesses don't care about who you where 2 years ago, they care about who you are now! (Time Sensitive)
Keep up the good work!
Don't have to add anyone as friends or worry about privacy or permissions. Clustered social graphs mimic how you meet and interact with your real life network.
Some of these may work on FB but many topical, time and event based relationships would not work within the FB friend request structure.
Could you explain why they wouldn't work with a public group, or a public event page, where there is no need for friend requests? And for the sake of argument, could you also say why I should trust you with my data instead of Facebook?