we are given PDAs during our first year by the SoP. Some of the programs are free to us and some they request that we buy. The professor will ask questions during classes and expect students to have their PDAs and look up the information. They will also beam info to students and expect it to spread throughout the class and for it to be utilized. we have rotations our first and second year as well so it does come in handy on those.
pharmacists may not use PDAs much but they should because they are terribly handy and can hold any information that is needed. i think that perhaps a lot of pharmacists do not know they are available. i have programs on mine such as micromedex, lexi-comp (both have drugs, diagnostic, monitoring parameters and the lexi now has a "calculator" that calculates all of your dosages for you), clinical pharmacology, sanford (very very handy), and the medical letter (again terribly useful).
like some of the others have said... you will definitely use them more during the 4th year rotations. we used ours during a part of therapeutics called "real world cases" where it was like a roundtable discussion about a patient.
i personally prefer the palm platform though i realize that pocket pcs are the "thing". pocket pcs are a little slower (from what i've read) but most users don't notice it. i have found that on occasion my palm is a little slower than i would like it to be (even with an expansion card) and i believe that whenever i do make the switch it will drive me crazy.
it probably is a good idea to wait until at least the third year to make a purchase of a PDA unless you are really ambitious.
oh and... laptops.... wouldn't bother with one on rotations unless you had time to sit around and type stuff up.