Sync across macs and idevices

How can I sync ratings or deletions of photos across Macs and iOS devices? I have an iMac27" and a MacBook Air. On the iMac I have all photos stored, 180GB. On the MacBook Air I'd like to rate, sort and delete photos, as it is more comfortable (mobile). Actually, the best would be to make this "clean up" operations on my iPad, and sync this back to the iMac. It would be even enough to sync the ratings (stars). That way I could mark with 1* star those photos that I would delete, go to my iMac, and delete those foots there. It is simply by far more comfortable to cherry-pick photos on a mobile device, then sitting in front the big screen.

Any idea?

Thanks

Marco