It seems pretty common nowadays to get e-mails with statements such as Sent from my iTouch and the like appended. This is analogous to the advertisements that HotMail used to stick on e-mail messages. Why do people want to send advertising copy with their e-mail? Didn't you pay for your iTouch? If so, why provide Apple (or whoever) with free advertising? My advice would be to remove such tripe from e-mails, or, if you can't, then be very ware that you are not in control of the image you project when using such tools.
Soundtrack: "I Robot" by The Alan Parsons Project.