Depends on the specific lenses you have. Optically, some of the older lenses are exactly the same as the newer versions.It also depends on which Nikon digital camera you choose and whether it works with the older AIS lenses.

As Larry says there are various "it depends", but I'll pitch in with a few thoughts as I also have an old F3 and I've owned 10 Nikon/Nikkor lenses (only one longer than 50mm by the way). One thing that I believe is true, but you'd want to confirm, is that you could use your lenses in aperture priority AE mode and manual focus (of course) with the D200 but not D80. Another is that it is possible to have the chip installed in the older lenses for AF, so if the lens merits this you might consider it. A few generalizations: the older ones are much nicer mechanically, albeit heavier, and easier to read for zone focusing. The older zooms are not nearly as good as the new ones. Nikon lenses tend to be soft at the edges, and you'll not crop them too much I think with the Nikon format (Canon "full frame" would be another matter). Also, if you Google "best Nikkor lenses" you'll find two sites on this topic. A goodly grain of salt is needed, especially in my view with the U.S. one. Some odd opinions (for example, he always shoots in jpg rather than raw, which for various reasons I find perplexing), but also useful material and, I suppose, lots of energy. The Nikon Compendium book is also worth a look for its coverage of the lenses.

Another thing worth considering, with the 1.5 cropping factor with the Nikon and the 1.6 with the lower priced Canons, the whole character of the lens is changed. I too have an arsenal of glass for my F3, but by going digital, I lose the functionality for which I bought most of the lenses.

For example, my 28mm PC-Nikkor shift-lens was never quite wide enough on the F3. On a digital body, it only has the coverage of a 42mm lens - which is not only of limited use, it is rather absurd. I bought my f-1.8 105mm because it was the fastest and longest lens I wanted to carry for photojournalism. I found the 135mm just a little too long for comfort, and the 85mm not quite long enough. On a dSLR it covers like a 157.5mm lens - a focal length that had it existed, I would have never once considered. The 35mm is about the only one that fits my kit. It becomes the equivalent of a 52.5mm normal lens. The 24mm covers it at 36mm, but leaves me with no real wide angle. I bought my f-2.8 200mm, because it was an ideal concert lens but it becomes a 300mm, which I never wanted.

A body with a full 24mm x 36mm sensor would restore their function, but in spite of ongoing rumours about Nikon being about to release one "real soon, now" there is little indication that they will. All of the new lenses are made to only cover the DX sensor, and many of the full-frame lenses are now discontinued. I suppose if Nikon did bring out a full frame camera, it could put them back in production in fairly short order.

Canon has a couple, but that means a very healthy investment in a camera that is surpassed so quickly. The Nikon D1 body cost $5,500 a few years back, and it would be difficult to sell it for anything now. No one wants old digital cameras.

In the meantime, I am greatly enjoying shooting with my Coolpix 8400, with a fisheye, 18mm->64mm component, 24mm->85mm zoom and two lenses left over from my first digital, the CP990 which still work fine on the current camera, giving me 2x and 3x focal lengths to 255mm equivalent. I vastly prefer the swing and swivel monitor to the optical viewfinders of the old SLR design. It is an alternative that has worked well for me.

Thanks for all the advice. I keep going back and forth on either the Nikon or Canon digital SLR and the use of my older lenses was a consideration. Will make the decision by Christmas.