As someone from the UK it is interesting to hear that the US view is of concern over UK holding a referendum. I have no particular view on the matter in question at the moment (UK role in EU) but it is odd to hear the view of the leader of a proud democracy is anti this referendum. Does the US have referendums? Or is it all left up to mid terms and presidential's?
Some individual states have ballot measures, which can be placed on the ballot by the governor, legislature, or petition of the citizens. There are many of them every year. I used to think this was a great idea.