Could you also display the DOI and use it to create a link?

Interesting suggestion! I don't know much about DOIs. How would I find the DOI for a paper/citation, if it doesn't already have one in the bibtex?

It's often somewhere on the website for a paper. New papers tend to have it right in the PDF as well (at least most of those I read). Look for "DOI" or the link starting with "http://dx.doi.org/". Usually close to the abstract or at the bottom.

I think this would be a great feature as it is a single universal identifier. It is more reliable that the paper url, which may or may not be present in the article metadata. It seems to be standard practice now that all new articles have a doi, and many journals are adding them retroactively.

For example

http://journals.aps.org/pra/abstract/10.1103/PhysRevA.91.033409

right under the abstract.

If I do an ISI Web of Science search, for example, and output the article entries in bibtex, I find that they all have a doi, but they don't have a url. So resolving the doi as the article link would solve a lot of problems for me!