I'm going into the medical field and wanted to know what is the best handheld device or PDA to carry around at the hospital. I know many medical professionals carry one around to look up drugs or obscure terms they may not know. I'm thinking about getting an itouch because it can also go online and you can download books on to it.

What is the best brand/ model to buy? I'm willing to spend a good amount of money on it if it is a good investment.