Did you see this project published on CodeProject and Google code:
PDF Viewer Control Without Acrobat Reader Installed[
^]?
As you have a source code, you could build with the target you want and make it compatible with your device. As this is based on the .NET Framework v.2.0, it should be highly compatible with Mono, as Mono is currently made well compatible with v.3.5 and
System.Windows.Forms
, so it is likely valid for Monotouch.
I've personally developed good amount of software with good compatibility with Mono, mostly tested on Linix and some on Mac OS X, without recompilation, but I never tried Monotouch.
If you succeed, it would very nice if you share your experience with CodeProject readers.
—SA