I have recently bought the sigma 30mm 1.4 HSM for the four thirds mount to use with my Olympus E-30. The lens I received had a very strong front fokus and I had to send it to sigma for readjusting. Now it's focus is spot on, but it would have been nice if it had been so in the first place.
Anyway, the 30mm 1.4 equals 60mm when used on the 4/3 2x crop, which is a bit longer than standard. I use it as a portrait lens, even though you can really see wide angle distortion when you use it too close to the subject.
Compared with the 50mm Zuiko 2.0, the sigma has one main advantage: It's autofocus is way faster and less noisy. Granted, the 50mm is a macro lens - but if I were shooting people indoor at an event, i would certainly prefer the sigma lens.
But enough talk. Images!