In the interests of full disclosure, I have only answered 3 problems on Project Euler, and I did them all myself, because I have the willpower to not look at other answers before creating my own. (I have the same username there: http://projecteuler.net/profile/jcurbo.png) Anyone looking to learn something and not just check boxes will do the work and exert the same willpower to ignore solutions already out there.

The core of this problem exists in education at all levels; the learner must be coerced or convinced that it is in their best interest to actually learn the content rather than cheat.