I wonder which one of the two cameras should I get. Here is one comparison. I've seen good photos on flickr using both cameras, so I'm not sure. People say that the Lumix's aperture is slower than the Olympus. EDIT: Also, is it possible on the Olympus to disable the bokkeh effect?
The bokeh is influenced by the aperture you choose. It is not an effect.
The wider the aperture you choose, the less depth-of-field you get which is what makes bokeh appear. With the Olympus you have more latitude to choose less depth-of-field but you can choose an equally large depth-of-field on both camera.
The Olympus ZX-1 is really nice and produce very good quality images for its class. It also handles very well because of its well-placed dials. I'd go for the ZX-1 except if ultra-wide-angle is very important for you.