Much of any "problem" you might have will be with the rear cluster. IF you use the widdest imagineable range back there it will have a huge impact on the gear spacing. I try to find tighter ratios like 13-32, and combine that with tighter ratios up front like 46-42-26. The real output depends on your wheel size but the spacing is independant.
An explanation of half step gearing can be found here:
http://www.crazyguyonabike.com/doc/p...e_id=56277&v=s