I used www.moneysupemarket.com to find some travel insurance for this trip.
Its a pretty good site, and compares the prices of travel insurance from hundreds of different companies. I settled for a reasonably basic travel insurance policy, but that has good medical cover which is important for the USA.
At 116 pounds for 12 months, its a third of the price than that of the travel insurance offered on the lonely planet website.
In all my years of travel, i have yet to have to use my travel insurance… and i am hoping that this trip will be the same !!