David Eubanks has done a real service to the industry by creating and refining these programs.  If you use them pay for them.  They are well worth the little he asks.

Kind of hard to work efficiently without a PDA these days.  In my opinion the PalmOne line is as good as these things get.

In my opinion Planetarium for the Palm works every bit as well as sunPath.  It also has the virtue of allowing for last minute changes as you stand on the set.  It will also track just about anything in the sky, day or night.

I highly recomend the Suunto line of compasses and clinometers for use in day exterior cinematography to track and predict the position of the sun.  The reletively inexpensive MC-2G works just fine.  At some point, though you will prefer the sturdiness and precision of the higher end units.

DDH Software are the publishers of HanDBase.  It's a great program for organizing information.