Accessing Galaxy Nexus as USB storage under Ubuntu 12.04 (Precise)

• Type "sudo apt-get install mtp-tools mtpfs gmtp".
• Connect the Galaxy Nexus to the computer with a USB cable.
• Drag down the status bar and tap the USB icon.
• In the USB computer connection dialogue, make sure that there is a check mark next to MTP, not PTP.
• Launch the "gmtp" program and click "Connect" button. You should see the contents of the storage of your phone.
• You should be able to drag and drop files between the gmtp window and another graphical file manager.

You can also mount the phone's internal storage and use any file manager or command line to manipulate the files and directories. The below instructions are adapted from here:

• Edit the file /etc/fuse.conf and uncomment the option "user_allow_other".
• sudo mkdir /nexus
• sudo chown : /nexus
• sudo mtpfs -o allow_other /nexus

Your phone's storage should now be mounted as /nexus and accessible to the regular (non-root) user.