You guys have any experience with those 12v "Puma" compressors you see on eBay? I saw one on Pirate the other day, seems like a decent option for the price and ease of setup.
100% duty cycle and 3CFM @ 90psi. Not bad for a 12v compressor that you can get ready to go for about $200.
I'd still go York but if you're just airing up tires it's another option.