deadsea - 2:53 pm on May 10, 2011 (gmt 0)
Agreed, its not blatant cloaking that is against Google's policies. I've loaded content into a page via AJAX to hide it from Googlebot in many cases myself.
But as SanDiegoFreelance points out, if you take it to any kind of extreme, Google would have no problem whacking your site with a penalty.
I've also seen posts here that indicate that Google may devalue your site if it thinks there are big empty sections of white space like iframes that it can't see.