A mobile web site project I've been working on has been recently been analyzed by a performance consulting firm and they came back recommending that we move all of our .css file links to the BOTTOM of the HTML to accommodate issues on the iPhone where .css files can block concurrent server requests. 

I've always known this to be true on most browsers when it comes to .js files--hence the common practice of putting .js file links at the bottom of one's HTML--but I've never heard this about .css files. 

I have yet to get a response from the consulting firm with cited references as to this being an actual issue on Mobile Safari. Has anyone else heard of this and, if so, know of any specific references that talk about it (perhaps from Apple directly?)