Ravenous:

The shape light is weird to use, but I've found it useful in several specific situations.  One is to simulate a large fluorescent panel light, especially those with a plastic lens covering the entire light fixture.

The shape forms at the hot point of the bulb representation, and the height by width dimensions are perpendicular to the axis of the bulb's base.  The best way I've found to work with it is to jam the bulb, head first, up to the wall or ceiling where I'm using the light, crank up the wattage, and use preview to see what I've got.  It's then a simple task to move it into position, then set the strength as appropriate.

Once you play around with this, you will intuitively know where the shape is in relation to the bulb.

Klebnor

Lotus 123 ~ S-Render ~ OS/2 WARP ~ IBM 8088 / 4.77 Mhz ~ Hercules Ultima graphics, Hitachi 10 MB HDD, 64K RAM, 12 in diagonal CRT Monitor (16 colors / 60 Hz refresh rate), 240 Watt PS, Dual 1.44 MB Floppies, 2 button mouse input device.  Beige horizontal case.  I don't display my unit.