i've got a bunch of basic questions concerning PDA's. i don't know anything about them, but I've noticed alot of ppl have been talking bout buying them for medical school. 1. what are pda's useful for (for medical school students)? 2. how do they work? internet connection, email, phone? 3. what are some good brands/types and around what price is a good amount to spend on a pda? Thanks!