I dabbled with Facebook back in 2007 for about a month and found it extremely boring so requested my account be deleted.

Dabbled with Twitter to track the official accounts of Microsoft, Intel and Cisco but got bored and ditched that too.

Had a Linked in profile for nearly six years with my connections consisting of those I'd worked for or with but got rid of that too in February as they just sent me stuff I didn't really care about.

 I don't miss any of them and most of the time I don't have time as work keeps me busy (I booked today off otherwise I'd not be posting at this time of day)