I posted something about this over on Ask.Mefi but I had absolutely no takers - I was pretty surprised.
I was playing around with one of my social network accounts, (believe it or not I can't remember which at this point), and noticed I could "import" contacts and see who from my contact list was already a member. I could also "export" existing friends as a CSV file. So, I went around to all my old accounts - LinkedIn, MySpace, Orkut, etc. and downloaded the contacts into my address aggregator of choice, culled duplicates and exported to a CSV.
Then I went around to all the social networks I had accounts on to try and import said addresses and see who already had an account. Facebook worked, was able to add a few more contacts to LinkedIn and even the newer Trusted Opinion. MySpace's is not working and I got a note back from their Tech Support stating such.
I made a huge gaff with YouTube. It said "import your contact list" so I did - thinking that it would THEN let me choose to send invites or, hopefully, show who I already knew that had accounts. Well, it auto-invited all 500+ contacts without giving me any sort of second step. Awful!
I've been pretty tired after work this week so I may have missed it but I've been surprised that there isn't a way to do this with Friendster, Flickr and even LiveJournal. I'd like to see more integrated features like this in Amazon, Last.fm and TV.com as well. It would be cool to allow additional sites like MetaFilter and IMDB to do this but they don't really have a "friend" setup. I was also very surprised to see that PeopleAggregator didn't let me do this - Marc Canter, what's up?!?
All this came about when I started using Twitter this week. Many of you know I'm the first to signup on nearly any Social Network just to see if they've hit that magic combination. Well, magic for me anyway. I have been bummed that to add any more friends to Twitter that I'd have to manually go through every email address and see who of my friends had an account. Dodgeball is another phone-based social service I'd have to do this with.
Here's the magic combo -
1. Allow people to choose to be publicly findable or not
2. Allow people to import their contact list from Plaxo, Yahoo! CSV, Outlook CSV, GMail, Hotmail etc to see who from their list ALREADYhas an account on said social network.
3. In addition to checking names and email addresses, based on the privacy settings of that user, check phone numbers (especially for mobile SNs like Twitter and Dodgeball), Web site URLs and IM nicknames.
4. Allow that person to then choose whether they want to invite friends NOT already on the network.
5. Offer to "alert" the user anytime someone matching their contact info shows up on that network.
6. Allow people to export their contacts in various CSV formats.
7. While I'm at it, allow me to take IM nicknames people have and auto-add them to my own YIM, AIM, GTalk, LJTalk, Skype, MSN, Jabber and ICQ accounts.
Here's what Social Networks are STILL missing IMNSHO:
1. Ability to choose a category to put your contact in. Flickr has very basic categories like Friends and Family. Orkut goes a little further and probably has most of the relationships in the RDF relationship schema. Facebook has a strange but somewhat standard set, as does PeopleAggregator.
2. What about allowing people to create their own groups ala LiveJournal and Orkut and then control which groups/types get to see what? Relationships + Trust.
Add a little encryption to ensure the trust is truly there and people wouldn't be so hesitant to join social networks. People would put much more of their info online if they knew they could control and define who got to see what.
That is the pipe dream...but first just allow me to see who that I know is already a part of these networks. Then we can begin to build our networks much faster.