I use Safelog.
http://www.dauntless-soft.com/products/Safelog/
It is pretty straightforward and allows to enter not only the hours in all the relevant columns but also aircraft types; journals on flights; approach types flown, then do some simple analysis on flights (not so good/useful this bit I have found). Printing out is not great but works as a written record.
I use it on the PC but there are also PDA versions.
I use it to record more information on my flights than can fit in the paper logbook and to ensure that I have added up the hours correctly in your paper logboook (you can specify dates to coincide with logbook pages).