Technology pop quiz!

One of the perks of being management... I'm getting a new electronic toy! (Believe me, though, it's a good thing I'm not just in it for the money. The increase in work is exponentially larger than the increase in pay.) I have the option of a PDA, a Blackberry, a tablet computer or a laptop. (But only one of the above, since this is the public library.) Cue me, slightly bewildered and overwhelmed. [Poll #1083708]

Seriously, I'm leaning towards a tablet computer, but I haven't done any research yet. If there are any reasons why this is a huge and hideous mistake, tell me now!