Best PDA and Cell phone in one device?

I'm a nursing student and need to buy a PDA for clinicals so that I don't have to carry all my medical books but can just put their programs on the PDA. Now I just learned that you can buy cell phones with an integrated PDA. I would really like to get one of these but I don't know what to look for to make sure that I buy a good one. What's important? And after the initial purchasing cost, how high will the monthly phone bills be with moderate use?

Thanks for your help!

You will definitely benefit from having a PDA as there are many medical programs for them. Both of my brothers are in medical fields and find them indispensable. However, I think (and my brothers agree) that there are not any PDA-phones out on the market yet that give you the best of both worlds. If you get one that is primarily a PDA you will sacrifice some phone functionality and vice versa.

You might find one out there that has enough of the functions that you need, or you could do like me and just keep your eye on the market and use both a PDA and phone in the meantime.

o2 xda mini or whatever you like

The cell phone part of the costs will be no different than any other cell phone - it's the same system, after all (assuming you don't use it for much data!)
The PDA part is harder. I have an O2 XDA IIs, which is more like a computer that happens to have a cellphone rather than a cellphone that happens to have a PDA.
The reason I like it is that it can store HEAPS of information, it runs applications I'm familiar with (like Word and Excel), and the screen is very usable.
It IS very pricey, however.

flybook. it's perfect, but expensive

O2 Atom supposedly be the best, but its expensive.

I like the Palm One Treo. It has great programs you could download. It's pricey, around $400 - 500, but you could make use of it.

The best cell phone and PDA is Motorola A780. You can't find any better.

i think the palm treo 650 but it is quite expensive