Interesting wikipedia page for this;
http://en.wikipedia.org/wiki/0.999...#Proofs
Edit: The main problem with this arises with the concept of infinity, the number 0.(3) is identicle to 1/3 because of the infinite recursion. To claim that 0.(9) is always slightly less than one is to ignore the fact that this is an infinitely long sequence of numbers, there is no end.