Subject: Traveller's watch
Following the lead of the wristwatch thread on what not to leave home without, I have a simple Casio calculator style watch that holds up to 50 phone numbers and dates, along with multi-time zones and the calculator function. It is very durable and is quite indispensible since it holds so much information right on your wrist, and if you had to simultaneously call home, figure out local currency, and find out what time it was in the U.S, you could do it easily. They only cost around $50.