Has anyone tried using ALL CAPS on meta heads such as on the title, keyword and description? Does it give you some boost on search engines using all caps?
check this out, result from google search - http://www.seo-informer.com/knowledgebase/terms/all-caps-title.aspx
No boost or benefit - in fact, it's tantamount to SCREAMING INTO SOMEONE'S FACE FOR ABSOLUTELY NO REASON AT ALL!!! In other words, it's just bad manners, and likely to cause your visitors to leave and never return. And yes, the bolded/italicized text in capital letters was just an example for demonstration purposes only.
Other than the fact that it can (and will) drive people away from it and straight into your competitors' sites.