While not strictly a gadget, I picked this up to protect that most iconic of gadgets: the iPhone.

http://www.eddiebauer.com/catalog/pr...sembleId=43064

While there are waterproof cases that you can buy, they run into the eighty dollar ( US ) range. Couple that with their being cumbersome and a heck of a thing to put in your hip pocket. For everyday use, on the iPhone 4, I use the Otterbox Commuter. It's more streamlined than the defender, less expensive, and it fits nicely in my pocket while offering a good deal of protection.
Considering how many times I would really NEED a waterproof case, this Seal Line is an excellent option. Good for that sudden shower when you're out, or crossing a creek or river. My phone, in its Commuter case, fits right in.
Last night I took it for a test drive in my cheese ball pool with a hurricane and a couple of beers. I played Words With Friends like a champ and never once fretted about the water. I was even able to snap a decent picture through the little window, though the flash is rendered completely ineffective.
I have an Eddie Bauer store in my town, so I was able to grab this without shipping cost, whatever that might be, but $25 buys a lot of piece of mind for any time you have to have your phone around water. They also had them for the iPad, some other tablets (Fire?) and one or two other phones. A handy thing for an adventure, to be sure.