More to explore:
felt play mats
Awesome homemade glitter play dough!
car mat / map of your neighborhood.
Super Fun DIY City Play Mat for Kids
Lay-N-Go Lego Mat - brilliant!
Totally doing this!
brilliant! lego mat that cinches up to a bag. though I am not sure my kids would stay on the mat... I'm thinking about polly pockets, barbies, etc.