Is their any websites that have any good info explaining which lenses and adapters can be used with the E-P1? Specifically concerning older manual focus lenses. Or even the GF1.

More or less any lens in existence that can cover a 4/3 sensor with the image circle can be used on micro 4/3 cameras. The only caveat is those with extremely deep rear elements that come very close to the sensor...they may hit the mount, and also those that don't hit, but are still very close have corner smearing due to the angle of incidence. However, the vast majority of lenses will fit the E-P1. Leica M, Leica thread mount, C mount cinema lenses (those with a large enough circle), Oly Pen F mount, pretty much ALL SLR lenses, etc (though if you mount EF lenses, you have no aperture control). Canon FD, Nikon, Canon EF, Leica R, Olympus OM, M42, Pentax K, etc, etc, etc. It's pretty much a universal camera. 


