I was hoping that something like the EyeFi wifi would work on the Sony Reader:
It's a SD Flash memory card with built in 802.11 WiFi capabilities. It's actually designed to work with digital cameras. Unfortunately, it only seems to send data from the Eye Fi card to a computer running their software on the network or to a designated photo sharing web site. It does NOT (as of yet) allow wireless uploading of files TO the SD card.
Too bad, as that would be pretty cool to be able to send books to your Sony Reader without having to hook up a USB cable. All without having to have the Sony Reader itself being WiFi capable. Still, even if this worked, it would not allow for Web browsing or checking e-mail (at least not directly).
Maybe one day they'll add the capability to do this or someone will figure out a hack to enable this capability. Though, somehow I don't think this can happen without some integration/two way communication to the device holding the SD card (ie. the card would have to tell the Camera/Reader that new files had been added and to update it's directory data and in the process, the card may or may have to be unmounted while being written to and re-mounted again after files have uploaded into the card).