Ed Breneiser, Wa3WSJ, sells antennas for hams that like to take their ham radio to go. I haven’t used them, but they look well-made, and if Ed’s experience with them is any indication, they work well, too. He always seems to be operating while backpacking somewhere or operating portable from a covered bridge.
Now, he’s added a PDA links page to his website. The page lists four logging programs as well as a program–HRR–that provides a bunch of functions, such as the ability to calculate dipole lengths, inductance, etc. While I haven’t tried it yet, HRR looks to be a very useful program. I tried developing something similar, but never did finish it.
Also included on Ed’s link page are links to other programs that might be useful to hams on the go. These include text readers, a personal diary, and first aid info. Great stuff!