Multiple Party Affiliation
Some states, like New York, allow a candidate to run for office in multiple parties, (e.g. Republican Party and Conservative Party or Democratic Party and Liberal Party.) I'm not sure how many states allow this, however.
I've become so disgusted by the neocon hijacking of the GOP that I now most closely align myself with the Libertarians. I do disagree with some of their core positions, such as open borders and some of their social policy issues, but I guess there isn't any party out there that someone would 100-percent agree with on everything. While the Libertarian social positions would be very appealing in many Blue-leaning states, they are a tough sell at best in the Red states.
I'm very comfortable with Dr. Paul's positions on the key issues and I think he will continue to attract lots of Libertarians back to him. I predict there will be enough hardcore Libertarians that may disagree with him on abortion and immigration enough to run their own slate of candidates, but that's most unfortunate.
Long term, if they are to gain any more traction, I think the Libertarian Party needs to do a substantial inward look of who they are and what they stand for. It's great to have a big tent, but if the tent is too big, there is the danger of losing focus and identity.
BTW, the Libertarian trend is to get away from a Left/Center/Right political spectrum, but to use the model described below. Take the quiz and see how you place.
http://www.theadvocates.org/quiz.html