From the Oly site re E-30

CREATIVE IDEAS COME IN ALL SIZES WITH MULTI-ASPECT RATIO SHOOTING.
Since photography is a form of expression that is essentially based on clipping a scene, framing is an important component of style. The E-620 provides four aspect ratios to frame your image to the desired proportions, including: the standard 4:3 aspect ratio that is suited for an 8" x 10" enlargement; the 16:9 aspect ratio that will display your images beautifully in widescreen television format; 6:6 for a square image, and 3:2 for the popular 4" x 6" print size.
More light reading on crop factors/aspect ratio's...

Cheers, Don