Your own deserted island

We're spending time in the desert southwest, at the oasis in Anthem, AZ provided by Deb's parents. A terrific getaway, with always so much to do and enjoy - and always the advantage of temps in the 100's. While among the cacti and lizards, there's also the great chance to daydream about life (some gurus call this the fulfillment of our human need for periodic refreshment; Jewish tradition reminds us of this idea every week with the concept of Shabbat). So I've been thinking about the old radio DJ question "what three things would you need on a deserted island?" (yes, vacation mode has finally seeped in). OK - they'd usually ask "what three songs", but with an iPod, it seems frivolous.
So for fun - if YOU were stranded on an island, or stuck somewhere remote, or even just off on your own by choice - what three items would you find indispensable? Play along, and have some fun.