I recently acquired a Toshiba Thrive tablet (Android Honeycomb, currently version 3.2.1), in part because it comes with two USB ports (one full size, one mini). The USB ports theoretically allow me to move files between my Ubuntu PC and the tablet by mounting the tablet as a disk drive on the PC. I say "theoretically" because Google recently moved to Media Transfer Protocol for handling connections over USB. This seems to be okay for Windows PCs and Macs, but for Ubuntu (and other Linux systems) it requires using the mtpfs package. I've found connections to be excruciating slow, and for some reason (probably a setting I'm missing), when I do get connected, all I see is an empty root and an empty Playlists subdirectory. Trust me, there are tons of files on the Thrive.
Fortunately, I found WebSharingLite File/Media Sync, a free app in the Android Market. (As one might expect from the "Lite" part, there is a paid version, rather economically priced.) I have a WiFi DSL gateway at home (and of course my laptop has WiFi). Running WebSharingLite on the tablet, I can connect via a web browser from my PC or laptop and upload/download files considerably faster than what mtpfs over USB seems to allow. (Again, though, I should stress that there's no guarantee I'm setting up mtpfs correctly, despite hours of poking around the web looking for help.) The connection requires a password; coupled with the fact that it's on a nonroutable segment, behind the firewall in my gateway, I think the security is adequate.
I can definitely recommend WebSharingLite.