ComScore's monthly rankings for America's leading Internet search providers were announced this afternoon, and it may not be much surprise that Google continues to top that list by a substantial margin. For the month of August, Google handled 6.8 billion US queries, up by about 200 million from July.

While Yahoo handles about a third of Google's volume to US Web users, its traffic loss for the month was not dramatic - only 50 million queries. Between July and August, MSN sites lost about 110 million queries.

But what may be curious is how comScore continues to count queries - essentially any kind of search across any of a company's properties. YouTube now counts, so the act of searching for a video is considered a query, and that plays right into Google's numbers. When you look at the breakdown, YouTube's 1.2 million queries now account for 18% of Google's US search numbers. Yahoo doesn't have a colossal video site; while Yahoo Video does exist, its search traffic appears to have been lumped into the 1.4% of Yahoo search traffic that comScore counts as "Other."

Take YouTube out of the picture, and the gap between Google and Yahoo narrows by almost 28%. By comparison, US "queries" on MySpace are actually down by 15 million for the month, to 560 million.

Any confusion there may have been over Google's search performance certainly didn't weigh on the company's stock performance too heavily today. Its NASDAQ value reached an all-time high at $560.04 per share, up $7.21.