Well you can't sync them to it without buying one of the programs in the app store that enable it but you can send it to your own email and then view it offline as long as it has been downloaded.
I don't have an iphone or ipod touch, but I do know that you can sync PDFs to a standard ipod. You simply open the PDF in preview, print, save to iphoto (it's one of the options under the "PDF" dropdown), and you can then sync it using itunes like any other photo.