Just downloaded Astroplanner, for Mac OSX (also comes in Windows and Classic Mac flavours). Looks like a very comprehensive set of tools and it sure beats writing everything down on paper. It's better than some of the other programs I've tried (like DeepSky Planner...although that's OK).
Version 2 will be out in a few weeks/months and, from the sneak previews I've seen, it will blow your sock off! It has superb new observation and image logging facilities.
Been using this for my spectroscope work for the last couple of years. Absolutely brilliant!!! Hundreds of catalogues to search, great observing plans updated frequently and 200% customer service by Paul. What more could you ask for!!
AP is a fantastic product, but better yet Paul Rodman the developer is one of the most supportive software vendors I have ever worked with.
In the last few days he built an add-on (via script) that generates ephemerides for eclipsing binaries in the GCVS that cope with 3 time zones (UT, home and remote observatory). The guy is a genius!
Astroplanner
