I bought a couple of old manual focus Nikkors from www.peterwalnes.com last week, to use with my D300. This has been made possible thanks to the D300's ability to setup non-CPU lenses so that you can even use matrix metering with these lenses. Amazing freedom! Suddenly the old manual focus lenses are usable again!
The first lens I bought is the legendary Nikkor 105mm f2.5 AI. I have always longed to own this lens; it feels like owning a part of history. According to Robert Rotolini, this (its rangefinder predecessor, to be exact) was probably the lens on which the Nikkor fame was built.
The second lens is also a 105mm, this time the 105mm f4 Micro Nikkor. I had always wanted to buy a micro lens, but the very high cost of the newer lenses had prevented me from buying them.
I haven't had much time to shoot with these lenses, but preliminary results show both are sharp and usable on the D300. With the f2.5, achieving accurate focus at f2.5 is tricky. Once I get a chance to take some real pictures (UK weather permitting) I will post samples.