Simply providing the ability to upload data only solves a small part of the problem. We run the CRAWDAD wireless network data archive (http://crawdad.org/) and the hardest parts are: convincing people to share data; ensuring that the data can be shared (much of the time this is not possible due to consent, data protection, etc); sanitising the data; and finally (and most time-consumingly) creating appropriate metadata so that the data are meaningful to other researchers.

The Research Data Alliance (http://rd-alliance.org/) is trying to solve many of these problems.