Is there any way to have the viewfinder output over USB so that I can grab the images live into Aperture for example or use an iPad as a large viewfinder?
I don't think so, but the technique you're talking about is called tethered shooting if you wanted to keep on researching yourself. I did a quick google and there was nothing current or recent that said you can
I looked for it a while ago. Appears the firmware does not support tethered shooting, nor does Panny have any plans of adding that feature to any of their cameras from what I remember reading. Almost any Canon or Nikon digital made over the past few years can. I wanted to set up a photo booth for my wedding with my GF1, but found I couldn't using any automated means. Luckily my step-dad's D80 does it.
Eye fi and shutter snitch on the iPad [ame=https://www.youtube.com/watch?v=H84EpXXcG_o&sns=em]YouTube - How To Directly Tether Your Camera To An iPad By Lee Morris[/ame]
Yes, that is an option, not particular impressed with Shutter Snitch in testing (I have an Eye-Fi Card), but I do use it for sync to Aperture using a Workflow. But it's slow and clunky. I was after a remote viewfinder more than a remote viewer for images already acquired. Hopefully the EyE-Fi update due this summer that allows for full connectivity to iPhone/iPad will improve that though.
