Connect via usb :-)
Run
rosrun usb_cam usb_cam_node
to grab the images from USB and forward to ROS.
By default, it will publish under /usb_cam, i.e. /usb_cam/image_raw.
To test this, run
rosrun image_view image_view image:=/usb_cam/image_raw
By default, this will display the image from /dev/video0; to change this, use
rosparam set /usb_cam/video_device /dev/bar