An interesting stat from mobile advertising 'enabler' AdMob: the conversation rate for ad-funded free apps on the iPhone is 10 times that of the full price versions. By conversion I assume they mean actual download and install onto the handset.

there's quite a bit of information out there at the moment that's showing consumer interest in ad-funded, both in mobile and on the web. (Outragous plug: I am loving the ad-funded version of music service Spotify). So could be we'll see plenty more companies making announcements in this space.