From Researching Virtual Initiatives in Education
A College is an institution (public or private) providing tertiary-level education but not at the level of university degrees.
However, in the US, the term "college" is often used generically to refer to any higher education institution which awards undergraduate degrees only. We would categorise these as "University colleges" - and if they offer postgraduate degrees also, we categorise them as "Universities".
There are similar issues in the UK and some other countries. For a fuller discussion see the Wikipedia article on college.
There is an automatically maintained list of these at Category:Colleges. This has currently (June 2009) around 20 entries but is still growing - and there are some issues of categorisation.