This is a very scary question, and a very heated issue: should employees be allowed to use personal devices for company work? On the one hand, smart phones and tablets are a huge opportunity to increase worker productivity (read: use them day and night). On the other, they may represent the newest, biggest vector of disaster, since they literally cannot be managed, but have access to corporate data.
I know that bringing a smart phone to the national labs is an absolute no-no. I also know many small businesses that flatly require employees to use their smart phone for company business, whether supplied by the employer or not.
Check out this great NetworkWorld article: