Private file sharing in the cloud

This week I was looking for an alternative to dropbox. Dropbox is fine for me as long as files are public and not in any way confidential. However some times I have a need to work together with colleagues and we don`t want to do so in privacy. So I was looking for a cloud service provider bases in Europe and with end to end encryption. The first I found was Wuala.

I am pretty sure there are more services like that around. Let me know if you know another one and I will add it to the article !!!