Prefilling knotholes before finishing

I have some cracks and knothole in my project that I dont want to fill with putty I would rather see them, gives it a good unique look.
I decided on a finish for it, which is going to be polyurethane.
Now I know this yellows and I am prepared to redue the finish in about 5 years, but if I just fill those cracks and knothole up with poly, then when it yellows I will be able to do nothing about it, because I wont be able to get into those places to sand it out.
Any suggestions for filling those areas?

Ross,
If you still have the knots, place them back in with epoxy or thick CA. Once they are back in, use thin CA glue on the middle of the knot. This will make the knot as hard (or harder) that the surrounding wood and as long as you are using poly (vs. stains) it will come out great. I have done this with good results before and will next time I have a situation where I want to keep the knots.

If you don't have the knots, I saw David Marks do the below on the episode that goes over Woodworking Repairs and Fixes, Pt. 1: Natural Flaws Episode 513. It actually goes over a few interesting methods. Check it out:

http://www.diynetwork.com/diy/ww_oth...556267,00.html

Dewey

Thanks Dewey this article should be very helpful!