Although the following shots are with the Olympus E-P1, the rendering is due to the Vivitar Series 1 28mm f/1.9, an M42 lens attached by way of first a Pentax M42 to K adapter and then a generic K to MFT converter.
red berries, blue sky
wildflower and moss
I've just written a review of this lens in two parts: here and here. More photos there, but the upshot is I love this lens!