SECOND:Permissions for much of the the ROS may be a little wonky. Your private machine allows you to become root (why not, it's yours!) Just type 'sudo bash', it'll ask you for the same password you logged in with, and from then on, you're superuser.
ROS -- WHERE: on the hackerspace workstations, in virtualbox images. Run virtualbox, and import the /vms/samples/ROS.ova appliance (except for NXT version, see below). This is Ubuntu 12.04-based. (Use username 'viki', same password for this VM. Save your own vm into /vms/yourname. Set memory at 3000M, and networking at 'NAT'. This user can use sudo to do priviliged commands on the VM.)
In addition to ROS, the 'viki' image includes gazebo -- a simulator of robots, sensors and objects in a three-dimentional world, generating sensor feedback and physics-based interactions between ROS-controlled robots.
ROS for NXT (Lego Mindstorm) -- WHERE: on the workstations in a different virtual machine. (The NXT plugins for ROS worked last reliably in Ubuntu 10.04, so we just made a 10.04 for this specific purpose.)
Use the Ubuntu 10.04 image found in /vms/ROS/Ubuntu-10.04-ROS-NXT.vdi [Use VirtualBox] Save your own vm to /vms/yourname. Set memory at 3000M and networking to 'NAT'. Username is 'Ubuntu', password is 'reverse'. This user can sudo to run priviliged commands.
Stock Lego NXT - if you'd prefer to use the somewhat clunkier, but more graphic, interface, the NXT drivers and programs from Lego are installed on the Mac (currently) next to workstation4.
USING USB Devices in VMs - Virtualbox uses a special group to allow people to access USB devices from within the VM. If you're gonna use USB devices from within a VM, please ask to be added to this group.