Tangential: If you believe in Nate Silver, Intrade is underpricing the Barack Obama contract by 20%+.
The contract that pays out $10 if Obama wins is currently trading at $6.70 per contract, implying a 67% chance Obama wins vs Nate Silver's 90%+.
Unfortunately, Intrade and American gambling regulations don't play nice so they don't accept US transactions. They also won't write you a margin account so you actually need to have funds in their system to execute a trade today.
Hard to say which party is inaccurately estimating the outcome, but given the regulatory hurdles around Intrade and the seemingly low volumes, I wouldn't be surprised if they're off.
It's really not difficult at all to get money into Intrade as an American. I had wires show up day-of if I did it early enough or next-day in every other case.
Also of note is that other betting markets were consistently higher than Intrade was for all of the last 6 months basically- there are a lot of theories as to why this may be, but it's regularly been 5%+ lower on Obama.