Know when Friends are Online
There are lots of people I 'follow" that i like to be able to see updates on. But it makes it really difficult to find out when friends are online to chat too. It would be really nice to have an option to mutually friend people so you know when they are on.
It would be cool if you could mark somebody's account, and then have it pop up in the notifications page when they come online next. Let's say you want to chat with someone, but they're offline or away. Just press a button, and be notified the instant that user comes back online.