Embedded mobile page?

[farlandlee]

I have a client who wants a mobile version of their homepage.  Normally, I use responsive design to accomplish this for the SEO benefit, but in this case the client wants very different information on the mobile home page than their regular home page.  I don't want to go to a dedicated mobile version of the page because they get a fair amount of mobile traffic and so it would probably have a significant negative impact on their SEO to do so.

So I was thinking I would add a hidden div to the home page which includes everything they want on the mobile home page and then use CSS to hide the regular content and show the hidden content if someone reaches the page from a smart phone.  What do you think about this idea?  Would I run afoul of Google's anti-cloaking "rules"?  Has anyone done something like this before?

Thanks!

[farlandlee]

I cannot imagine that there is no one in the learned community of SEOmoz who doesn't at least has an opinion on this matter.  Anyone?