If jailbroken, just copy them to iPhone via SSH or some other method and use any PDF viewer to view it. I suggest iFile.
Though I'm sure there are many other programs on the App Store that will do it as well. For instance, with Zumodrive I can just copy and paste the PDF file to my Zumodrive folder, open up the app on my phone, and stream the PDF file that way since Zumodrive supports the format.