There's a big lack of social interaction on Photosynth's current website.
As someone who has spent a lot of time on the forums, it's really frustrating to spend time answering someone's question + feeling like you don't have any idea if they'll ever see it because they were never notified that anyone had replied to them.
When someone signs into their account, it should be obvious to them that:
:: they have three replies to their forum post(s),
:: seven new comments on their synths,
:: sixteen people favorited their synths,
:: their synth was featured on the Photosynth homepage or Bing + got lots of views
:: their synth was shared, retweeted on Twitter/reblogged on Tumblr, and commented on there
I would like the option to get email notifications for all of these and for some of them I think that the default should be set to receive the notifications - specifically being featured on the homepage (so they can enjoy it while it's happening) + forum replies.