I don't have a digital SLR yet, but generally there is an effective magnification increase when using a 35 mm lens on a digital due to the smaller image capture area vs a 35 mm film frame. This factor varies by brand but generally seems to be 1.5-1.6 with some a little higher.
Canon's website, for instance, describing the EOS Digital Rebel's compatibility with existing EF lenses says:
Designed exclusively for the EOS Digital Rebel, the new EF-S 18-55mm f/3.5-5.6 lens offers precision and quality. It is compact, lightweight, and covers the standard zoom range of approx. 28-90mm (in 35mm format) with smooth operation and superb resolution.
That makes the factor somewhere around 1.6. So a 100 mm lens would magnify like a 160 mm telephoto when used on a digital.