Judging from what the both of you are describing, I would go the way of the Compaq iPaq.  In particular, I would recommend the 3765 model.  Of course, there are other PDA's from Palm, Sony, Toshiba, etc.  Personally, I have a Palm.  It works alright but the techno geek in me wishes for the iPaq 3765.  I had the opportunity to test the iPaq for a few days and I have to admit that I am absolutely impressed by it.  Playing MP3's on it was a breeze and with it's ability to use Compact Flash cards it was absolutely great!  I was only able to test a small movie file and it wasn't as good as a desktop but pretty impressive as far as PDA's are concerned.

One thing that is keeping me back from buying it is the price tag though.  At $449-$499 a pop, I can't justify buying one...especially after buying a laptop.  So, I'll stick to my trusty Palm Vx and pray that my employers are feeling generous in the coming months...hehehe.