Thank goodness for this thread we threw out our foam mats! Don't like taking chances like that esp since there's enough chemicals around to harm us already. We went to the melb baby and toddler show last weekend and got a Dwinguler bubba mat. We got the medium sized one for about $150. Much more expensive than the foam ones but really good quality. It's also much easier to clean as there are no crevices for stuff to be stuck in between. DD loves the colourful pictures and it's got pictures on both sides too.
Caixin - the Dwinguler mats are made of (at least partially) PVC - that's not a chemical that is kid-friendly despite it being "allowed" under various consumer laws.

UPDATE - hmm - did some more research, apparently there are different kinds of PVC...people (i.e., purchasers who review on Amazon) seem to be OK with the type of PVC in these mats...sorry, Caixin!