I am a first year coming in, so I don't have a lot of first-hand experience with what is going to be needed yet. However, I have supervised a University computer center for 2 1/2 years and most would consider me somewhat of a techy. I have a Pocket PC & I just bought a laptop to begin med school with.
PrettyDoc, I don't know whether or not the investments are worthwhile. That is a decision you will have to make, but I have just finished doing some extensive shopping for PDA's & Laptops and thought I'd pass along my picks to you.
PalmOS - Target is selling the Palm Zire (Palm's low end, B&W display, basically an organizer & address book, lightweight & compact) $79.99
Pocket PC - Sony Clie - Best Buy (highly functional, color display, lightweight) $179.99
PDA's - Also, if you want to buy a cheap PDA to function for what you need. Do some research to decide what you like, and then buy a used one from eBay (prices range from $55-200.
Laptops - (I am going to give you 2 options in different price ranges)
Toshiba Tablet PC - Very new technology, touchscreen, just like writing in a notebook, attached keyboard, very functional and fun. Good Reviews
$2200
Fujitsu Lifebook S2020 - (I just bought this machine last week and I absolutely love it) AMD 1900+, 256 DDR RAM, 40 Gb HDD, 13.3" display, only 4 lbs, CD-R/DVD Combo Drive, Great Reviews, and integrated Wireless Networking (both 80211.b & 80211.g) $1340 if you call them and tell them you are a student they will give you a 5% discount.
http://webshop.fujitsupc.com/fpc/Ecommerce/buildseriesbean.do?series=S2
My personal pick was the Fujitsu b/c it had the integrated wireless (no antenna sticking out of a card), DVD/CD-RW drive (so I can watch movies if I need a break), and most importantly it is very small and lightweight while not sacrificing much screen size. Most ultralight notebooks have a 12.1" screen while this one has a 13.3" screen, and when closed is not much larger than a sheet of paper.
Sorry this reply is so long, but I just wanted to pass along the info that I have found.