To use a Samsung Galaxy Nexus as a media device (MTP) there is a utility called gMTP.
sudo apt-get install gmtp mtpfs mtp-tools
NOTE: Unfortunately there is a bug in the 64-bit version at the moment (https://bugs.launchpad.net/ubuntu/+source/mtpfs/+bug/936165) – which means it’s not all that useful to me at the moment.
