I was wrong. The N900 version of Pixel Pipe *does* (yay! my apologies to the PixelPipe folks!)  allow sharing of unlimited number of photo as follows:

  1. In the Photos app, touch the top (where it typically says "All Images")
  2. Tap "Share Images"
  3. Select as many images as you want to upload
  4. Tap "Share"
  5. Tap "Share via service"
  6. Under Account, select your PixelPipe service
  7. Tap "Share"

It works great except when you lose connectivity. Then PixelPipe due to no fault of their own but due to Nokia's brittle sharing infrastructure doesn't retry when you re-gain connectivity. This retry "seamlessly when you re-gain connectivity" is what ShoZu does so well. It's not a big deal if you only load 1 or 2 photos. It is a big deal when you upload dozens ; then you have to figure out which photos were uploaded and then go through the above 7 step process for the remainder of the photos.