Chicopee-
How would I open a PDF in AutoCAD, even as an OLE object, and save it as a DWG? Are you suggesting saving the raster product into the "DWG" drawing? Sounds interesting- I've often imported raster (BMP, JPG, TIF, etc) files into ACAD, and saved the result, but I haven't yet discovered how to do this with PDF. Interesting idea.
Now If I could do this, I'd have access to viewing my PDF's with any ACAD viewer. However, on the face of it, this seems a bit backward, as I haven't found a "free" one yet that's worth using. Even the suggested BRAVA product costs $345 if you want to view any of your OFFICE documents, or mark up any comments ... And the question of viewing 3D Models is still open, as I still haven't discovered a free-ware program worth considering for that, either.
I get all the viewing & mark-up capabilities I need, circulating WORD dcouments with inserted raster versions of my documents and images, and as I've already purchased my OFFICE suite, the cost is already covered (not the same thing as "free", but lots of folks don't have to shell out extra for this functionality). A significant added benefit to this approach is that nearly everyone already knows how to use the tool, or has a secretary who can help. File security is a non-issue, as the embedded raster file almost NEVER results in an editable version of the original drawing. That level of security is available tho, for those who have a copy of one of the MANY free PDF writers and viewers available. ALL of this completely includes EVERY CAD format, including ACAD's DWG.
None of this attacks the original central question of conveniently viewing large directories of ACAD "DWG's" for free. Hmmmmm...
Tks-
C. Fee