Leatherman Squirt
The mainstay for both amateur and professional tinkers and tradesmen, this miniature version of the popular Leatherman tool is literally small enough to fit on a keychain. Available in blue, red and grey, it measures only 2 ¼ inches (5.5 cm) and weighs less than 2 ounces (60 grams).
It's $40 from The Sports Authority.