Review of OwnCloud powered by the Slant community.
Ranked in these QuestionsQuestion Ranking
Pro Open source software
Pro You have full control with your data
Only chose a provider or host it on your soho-server.
Pro Allows selective sync
Desktop clients offer sync almost as versatile as dropbox.
Con Not plug and play as Dropbox etc
You may need some help installing it on your web space, though some providers offer free install server.