Olympus makes an adaptor and I assume lenses for your camera. Circuit City lists it at their web site under digital camera accessories: <A HREF="http/www.circuitcity.com" target="_new">http/www.circuitcity.com</A>
I plan on getting something similar when I get my cam (haven't picked it THE ONE yet).
Adaptor lenses can cause vignetting (darkening the corners) at wide angle setting of the main lense. Aftermarket ones might not fit quite right and might be more likely to cause problems. However, many people use them with good results. Just make sure it fits correctly and doesn't interfere with the main lenses motion.