You're getting a couple of seconds of content not positioned correctly. You might want to try putting the main jquery and the lightbox (or whichever one is handling all those blocks) javascript in the head, to make sure that all of those images are being handled by the javascript right away. As it is, they aren't being handled until everything else gets done on the page. One or two .js files in the head won't slow your page rendering enough to notice.
I would also take all of the "boilerplate" CSS and put it into one file and run it through one of those CSS minimizers, like
http://csscompressor.com/ Then I would have one extra "overrides" .css file that gets edited for custom styling, overriding the "boilerplate" CSS. That way instead of the browser having to request, download and process seven CSS files, there would only be two, and the big one would not have any whitespace or comments or other stuff the browser has to parse past.
And finally, in my opinion anyway, you have far too many blocks on one page. I'd cut it off at about the same level as the sidebar, five rows instead of nine.
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