Aaahhh, the "Crackberry" as it is otherwise known! DH always swore he wouldn't have one of these as once you've got mobile email, you really ARE never out of reach of the office, but his new job has given him one and guess what? He's on it all the time now.
If your DH is at all the addictive type of personality, I wouldn't get him one or he'll be foever tap tap tapping away on the bloody thing.