The best way to go would be the Olympus E-510. While the Canon and Nikon make excellent cameras, the E510 has the self cleaning sensor (They invented it), Live screen on the back (They invented it) Canon and Nikon have this on their semi pro cameras, built in Image stabilization (Canon and Nikon don't have this on any cameras, just a few lenses).
It is a 10 MP camera on a 4/3 chip which means it is equal to a 12 mega pixel camera on the system that Canon and Nikon use.
The camera comes with 2 lenses, a 14-42 (28-84 mm 35 mm equivalent) and a 40-150 (80-300 35 mm equivalent) for only 659.99.
Between the Nikon and Canon the advantage of the Nikon is the camera is smaller and the lens selection is nicer, Most people looking at the D40x, 10 MP camera go with either the 18-135 (Canon has nothing like this) or the 18-200 VR (Again Canon has nothing like this). Nikon also has a 5 year warranty standard on all of their lenses.
You will get a great picture with all 3. I would avoid the Sony. The ability to use Minolta glass should not be the deal breaker as the Minolta glass is an old design made to be used on their old great film cameras, not digital. The Olympus glass and Nikon glass mentioned are all digital specific glass. Canon has a few diital specific lenses.
Sony also comes with the least coverage when it comes to warranty.
I am only to happy to help you if you have any questions. You can call me at my office tomorrow, Thursday at 212-753-5128
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