PDA and software

Hello!

I hope to be starting the program in Jan 08. With my GPA of 3.87, I dont see me not getting in. My question is about Pda's. I have heard that they were extremely useful. Can anyone recommend one? Cost is a concern or I would have upgraded my cell phone for a pocket pc/phone. I saw one at best buy for $100 and it had 32mb of memory. Is this enough memory? I dont plan on using it for anything else but the program. Also, what about software? Where can I go for this? Online, at the bookstore? Thanks in advance.