Reviewed: Olympus M.Zuiko Digital ED 300mm f/4 IS PRO
Get Olympus Digital ED 300mm f/4 IS PRO at B&H Photo. HIGHLY RECOMMENDED. This may be the very best lens available for Micro Four Thirds.
What a useful lens. I greatly enjoyed using it, which is definitely not something I can say about the equivalent 600mm lenses on Nikon or Canon.