The CDC ACM is a standard profile for USB to serial adapters such as the one built in to the u-blox range of GPSs. There’s quite a few pages on the Internet referrring to people having success building and using this on Maemo Diablo based device such as the Nokia N800 or N810 but I couldn’t find binaries or concise instructions anywhere.
Short story is that the kernel modules are easy to build and use and successfully work between a hacked up USB host mode N800 and a u-blox Antaris 4 GPS. It should work on other devices as well.
More information is on the wiki, including a binary tarball, instructions, instructions on building your own module without installing all of scratchbox, and a list of the other modules included in the package.