I do not know of any at this time.
I wonder if Sedo, Namedrive, Afternic, Fabulous, 1plus, or any of the other heavy hitters will step up to the plate and make a parking page for .mobi's?
I spoke with Moniker (traffic club), Sedo and ND and they all said mobi compliant sites will be up within next few weeks.
Before I get to develop my mobis, I parked majority of them with nd and used a basic template and it looks fine. I don't consider parking pages to be "content" so I am hoping mobi folks won't suspend me
Godaddy has free hosting for any domain you register with them and a website builder for .mobi.
They have an RSS feed, so I was able to quickly put something on my TravelAlert.mobi. It needs some tweeking to make it look better, but it's a start. I have to figure out how to get rid of all that empty space near the top.