[NateDad]

It's like your own personal google drive / dropbox / git repo

It's a content addressable storage system. There's plugins to import or export from various major services like foursquare, twitter, etc. and plugins let you store stuff in S3 or mongo or google cloud storage, etc.

[spondyl]

I suppose technically running something like OwnCloud with a plugin to fetch your content (text/photos etc) from the various social networking APIs would look near identical from the outside?