I'm currently working on a non-traditional "pay for downloads" site specifically targeted at iPhone apps to begin with. I have taken the plunge, registered as an LLC, and the site is almost completely built (expected launch in < 2 weeks). I will post on HN when I do launch but if you want to know more about it or are interested in being part of the launch shoot me an email at matt dot sencenbaugh at gmail

Sorry for the plug.

As far as a lite version of apps I think its a dangerous path.... I think it can be a valuable tool but only if you find the right balance between what features to include and what to lockdown in the lite version. In the end I think it really depends on how the initial launch goes. If you find that you aren't getting much traction perhaps you should release a lite version for a few days. If after a few days you notice that the lite version hurts your sales... simply remove it.