Tonight I have been testing DOF, with the following set up;

I used my D70s, in aperture priority, ISO 200, WB-A, and stepped through the range, end to end. Note, objects are 500mm from Camera, and 100mm apart. Distance to step out glue stick, 1500mm.
You can via the entire f-stop range at http://www.pbase.com/oz_beachside/dof_test_80200 , but here are a few.
200mm - 2.8

200mm - f4

200mm - f8

200mm - f22

It was too dark, so there is camera shake, but DOF is my testing.
Cheers,
Oz