The resolution of Film and digital are not directly comparable even ignoring the fact that different speeds and brands of film have different grain size, and so resolution.

The heart of the matter is analogous to the difference between pixels per inch and dots per inch. A single pixel contains a lot of information, it defines a scale of brightness, a scale of hue, and a scale of saturation. A single dot is merely black or white, cyan or white, magenta or white, or yellow or white. because of this you need a big square full of dots to represent the full range of information present in a pixel.

Many people have embarked on online comparisons, most with near religious interest in one or another outcome, so I don't think it's worthwhile to track them down and link them. Both film and digital have advantages; film in crisp line, and digital in smooth tone.

Outside of a controlled studio environment, or for very specific subjects or visual effects, digital will give you more useful results. Very soon the question will be moot as buying and processing film is becoming harder over time, and likely will for the foreseeable future.

For 6 megapixel digital SLRs-- the Canon EOS 10D, the Nikon D100, and the Fuji S2 Pro (which actually has 6 megapixels but uses sophisticated interpolation to simulate 12 megapixels)-- resolution is close, but not quite equal to 35mm film. But overall image quality can be stunning because color quality is excellent and noise-- the digital counterpart of grain-- is nearly absent. For 11+ megapixel digital SLRs, resolution is superior.

In typical consumer cameras the resolution is not limited by the number of pixels, but by the camera's optics. Not only are a certain number of pixels required to equal a SLR film camera, but also superior optics.