How can I display image formats not supported by the email app, e.g. TIFF? As I'm using K-9 Mail for my email app, sometimes I get a tiff attached to the mail, but I cannot watch it. Even Tiff2PDF will fail :(.

Any idea how I can get this to work?
The picture viewer of my HTC Desire work fine for TIFF...

Do you try Astro?

BeamReader is able to do it, but it's expensive... However, they offer a 10-day free trial.