Has anyone tried to work with a computer productively while flat on his/her back? I spend a lot of time sitting and it's unhealthy; long-term, it leads to circulatory problems. My ideal set-up includes a flat area to lie on (maybe an inversion table set to near-horizontal), an adjustable rack to hold 4 24" LCD panels, an inclined overbed table to hold a keyboard and magnetic mouse/pad. Has anyone gone down this road? Any commercial products out there?