How Many Social Networks Are You Still Active In?

I’ve received yet another invitation to join the social network Hi5. I’ve no time for that and am certainly not interested to join H5 anyway after seeing so much negative comments from the users about it. 

How many social networks are you still actively participating in these days? For me, it’s just Facebook, LinkedIn and Twitter. Those that I’ve joined but not actively involved anymore (not even login!) are Friendster, StumbleUpon and Digg.