Can my SLR be converted to be a digital camera?

I have invested allot in lens and would like to used then in a digital format with out giving up my first born.

the answer is no. do not worry, depending on your lens mount (be it nikon, canon, olympus, minolta or pentax), you can still use them for digital slr of the same brand/mount. the only way i can think of to convert a normal slr camera into one that could take digital photographs is to create a custom built digital back that is mountable on the specific slr. but that will cost a bomb.

There did used to be a digital fim cartridge that sat in the back of the camera where the film goes. I haven't seen one for ages.

In short... no.
You can still use your old lenses on new digital cameras.
However- if you're looking at most of the consumer and semi-pro DSLRs their sensor's are smaller than 35mm film. This has the effect of cropping all your images- or in effect- giving you more zoom.

So- your old wonderful 50mm lens, will be a new wonderful 75 or 80mm lens. (multiply by 1.5 nikon or 1.6 for Canon and others).

The newer lenses are designed to work with the smaller format sensors- and are therefore smaller and lighter- which is nice.

Or- you can get a 'full frame' DSLR (like the Canon 5D for instance) and all your lenses (if you're a Canon guy) will work without a crop factor.

It depends on your current camera. Or rather, on the lens mount. If it's anything from the last 15 years, probably YES.
Canon and Nikon have a nice selection of digital SLR bodies,
Pentax has a few models,
Minolta (Konica Minolta) had a few and now Sony's taken over their lens mount.
And if you're using Leica, you're used to paying an arm and a leg anyway - they have a digital back for the R8/9.

No You can't.
Buy a new Digital SLR camera.
I recommend you to buy canon products.
good luck

I don't think you can. I figure the important question is if you can use the lenses you invested in on a new digital camera.

If you use the older Canon lenses they sell an adapter for use with pre EF lenses.

Amazing how many people answer a question without knowing the truth. The correct answer is YES you can do this. A company called Silicon Film provides just what you are looking for. The next question is why do you want to spend so much for so little performance? I would not be much more expensive to get a dSLR and nice lens for a lot more performance. If you have some very expensive older lenses then buy a lens adapter and use those lenses in manual mode on the dSLR.

Most camera manufacturers engineer their new digital cameras to be backward compatible with their old film camera lenses.