With the announcement of the D3/D300 I was starting to think whether it wouldn't be time to upgrade from my D70. Being cheap I first thought of the D40X, but then read that it only supports AF-S and AF-I lenses. My Nikkor telezoom is only AF, works great on the D70 but I guess would no longer have autofocus on the D40X? I also have the Sigma 50-500 (Bigma) and I think that too would no longer have AF? So how should I upgrade? D200? Or even throw in the big bucks for a D3? Finally, how can I clean the chip on the D70? I got dust on it, then blew into it (my bad) and spit ended up on the chip. So how do I get rid of that?