Heads up to the blogosphere:

Obama's adoring fans in the media have consistently put the turnout for yesterday's rally in Portland at 75,000+, gushing that it was the "size of a city." Obama himself is claiming 80,000 in a new ad and Reuters is claiming 160,000! No doubt they are inspired by the success of fellow goebbelists in inflating Iraqi civilian death figures from ca 60,000 to a mind-boggling 2 million (per turncoat radio jock Jay Diamond).

However, Freeper "Wil H." has applied Google-Earth's ruler tool to the images from the Portland rally and has come up with a figure of less than 43,000.
This is based on a measurement of the rally area and an allowance of 4 square feet per person (quite crowded in a large area) and does not subtract for the large open areas around the dais or the other empty areas plainly visible in the images.