That's not the biggest issue for me. Often the PDFs that get posted are interesting enough for me to want to archive and read more in depth on the bus, when I

That's not the biggest issue for me. Often the PDFs that get posted are interesting enough for me to want to archive and read more in depth on the bus, when I don't have an internet connection. Scribd makes this a royal pain in the arse. Also, I strongly prefer the native feel of a decent PDF reader over a slow Flash UI running in the browser. (no, Adobe doesn't count as decent.)