SMAX: Yes, I have looked at a lot of the new DSLR units and have been really interested in what they can do for me and my particular needs, but at this point in time, I don't have the $2,500. that it would cost to replace the optical equipment I have now. In fact, to get what it would take to make a suitable replacement, I'd have to buy two units and that's not within my budget unless I win the lotto. Back in 2003 I saw an article in POPSCI that detailed a device that would take the place of a standerd 35MM film package in and SLR but record the shots in digital form. It was supposed to be priced around $600. but that would be cheap if it was really available. I have taken apart a few discarded digital cameras and played with the CCD devices some, in an attempt to make a digital capture device to work in the body of a SLR unit. There are a few stumbling blocks that I can see why a device to retrofit a stand 35MM SLR won't work, and the biggest is the time needed to capture a frame with adequate light and still maintain a fast shutter speed that is the main reason I still use a 35MM SLR. For now, I will scan my best shots into the computer with a scanner set to 2400DPI, yes, this takes a lot of time and uses a lot of memory space, but it's the only way to get all of that picture information into a PC and not be worrried about pushing the limits when enlarging the shots to isolate the picture elements I took the photo for in the first place.
I understand...depending on the lenses you would be after and level of camera you would want, $2,500 might not even be anywhere near what you would need to spend. If you wanted a "fast" (i.e. lower aperature setting) 200mm lense, you are talking anywhere from close to $1000 on up, depending on brand. And don't even get started on a "good" 500mm lense with lower aperature settings...you could be talking $10,000 or so (guy we ran into in Alaska had a 500mm or 600mm for his Nikon that was like $12,000). And then there are the camera bodies...while something like a D60 or D80 will be less than $1000, if you want more of a "pro-sumer" level camera, then a D300 would be about $1800 and a D3 would be more than $4000.
As to CCD sensors, be careful...not all CCD sensors are created equal. If you took one out of a point-and-shoot, then it will certainly be smaller than those typically used in DSLRs. Then there is the issue of shutter lag...don't know if that is a CCD issue or something else, but point-and-shoot cameras tend to be way worse than DSLRs when it comes to shutter lag. If it is tied to the CCD, then putting a point-and-shoot CCD in some film camera as a "conversion" would not work so well. Shutter lag has ruined more than a few pictures I have tried to take.
[soapbox] Backup = good...No backup = bad!! [/soap box]