[derefr]

Would having to use the (free) Dropbox iPhone app as an intermediate step bother you?

1. Sign up for Dropbox, if you haven't already; put PDFs you want to read into your Dropbox, and, obviously, buy an iPhone.

2. Install the Dropbox iPhone app.

3. In the Dropbox iPhone app, mark the PDFs as "favorites," and they'll be synced to the iPhone's drive, accessible whether or not the phone is online.

There are all the "network drive" applications as well, of course, but I think this is the best of both worlds: if you're at home the LAN sync will negate any extra bandwidth usage, while if you're out somewhere you can still pull the file from the network (once) and then keep it stored locally from then on. Then again, you can't do the "promiscuous sharing to anything around me that can speak Bonjour" this way, but I'm guessing you probably don't want people pirating books off your phone anyway :)