This page is a place to collect information about how to use ROS in conjunction with other popular systems such as Matlab, LabView, or SciPy. See this thread on ros-users.
The IPC-bridge package allows for publishing and subscribing to topics within Matlab.
The rostopic echo command with the -p option produces tabular output that can be imported into Matlab/Octave.
The bag2mat.py script in starmac_tools produces a Matlab (binary, version 5) .mat file from a bag file input.
Some discussion is at http://answers.ros.org/question/522.