I hate to be a pendantic wanker, but as a card accepting merchant who actually follows the rules (and gets yelled at by many a fine customer in the process) I have to verge a little further along the off topic road...
Writing "SEE ID" is actually not acceptable according to Visa/Mastercard and a Merchant should demand that you sign the card in front of them before they process the transaction. Of course you are free not to sign the card, but then the merchant should not accept it.
The reason is that signing the card indicates acceptance of the cardmember agreement, and without doing so you and the card issuer have never really formed a contract. Look on the back of your Visa/MC and it will say "Not Valid Unless Signed" which means signed not "See ID".
The tricky part of this is that if you write SEE ID and your card is ever stolen, and Visa finds out that you wrote SEE ID instead of signing it, they could refuse to cancel fradulent charges due to your failure to sign the card. Or even worse, from my perspective, they could hold the merchants accountable for the fraudlent charges since they accepted an invalid card.
See the following links for more details...
http://usa.visa.com/merchants/risk_management/card_present.html (go to the very bottom of this page)
http://www.denverpost.com/headlines/ci_6787955
/RANT
Wow, I had no idea. You can bet my Visa has my signature on it now. I'm only 21 and do not even come close to having the means to be responsible for fraudulent charges! I will forward those links to the people I know who also request ID on their credit cards. I've come to realize that all customer service workers who follow the rules get yelled at - I'm one of them that gets yelled at frequently for following them.
And to whoever had hand sensors in their dorms... wow. I am in college and we don't have anything near that fancy, just the swipe cards required to get in. With all of the crime going on at colleges, that seems like it would be a great idea. Too bad it's not implemented here.