Here's my view;

Doesn't it have subgroups? you can make your 'friends' into 'sets'...

Ahh, sets. Nice. I'll look into it.

I guess it can get unweildy.  Facebook groups, networks, would be easier.

I just did an event. I don't think you can RSVP

Some more screenshots;

.

What do you mean by "Omnidrive!" up there? Do you mean you'd rather spend twenty bucks on Omnidrive, or that Omnidrive is overly expensive like Pownce?