We know how significant usage of both mobile phones and social networking sites are, well lots of the mobile phone manufacturers and networks are plugging phones that offer easy access to SNSs (see UK advertising campaign from 2008):
There's also a forthcoming 'Facebook phone' that will offer much cheaper access:
Finally, the SNSs too have been active developing apps - the best being the Facebook app for the iPhone.
Anyway, all this is to make the point that technology doesn't remain static; it's developing in response to new social trends (e.g. popularity of SNSs, desire for permanent networked connectivity, constant 'intimate co-presence' facilitated by SNSs etc.) - trends which it plays a role in developing in turn.
Existing technologies such as mobile phones received a makeover to support the growing popularity of networked practices - e.g. smart phones developed a capacity for web access, email and other data services, still and video camera for shots that can be uploaded and shared.
So, camera-equipped smart phones which make it easy to upload pictures to sites like Facebook or Flickr might be said to be responding to existing - although still newish - practices but also create new social media behaviours of their own.