incrediBILL - 12:15 am on May 1, 2010 (gmt 0)

I segregate 'cache and other views' into a separate Analytics report, and see it runs from under 1% to less than 5% (usually 1% or less depending on the site).

To appear in GA implies javascript running.

Scrapers scraping cache tend not to enable javascript to hide their activities.

I catch them loading images via google's servers.