So it turns out that VitalSource books are printable. I captured the printer output with Adobe PDF "printer" (although there are several other programs out there for this -- including many free ones). However, my new PDF was in raster form and thus not searchable. I opened the PDF with ABBYY Fine Reader, did OCR, then saved a new PDF with ascii text underneath the raster pages. The original .vbk file was 13 megs. After tweaking with the output compression settings on ABBYY and saving a few drafts, I produced a PDF of what I consider identical quality (checked with zooming and I have a pretty good eye for colors and detail) for 15 megs.
Ta-da!
