Bond's use of gadgetry is evident in the novels but it was in the films that they really came to the fore, becoming one of the key elements of any good Bond film.
1. Aston Martin DB5 (Goldfinger & Thunderball) - I make no apologies for the DB5 winning another category. It's a marvellous car but its the Q-Branch modifications that enable it to claim top gadget; revolving licence plates, tyre slashers that double as spinner hubcaps, a passenger ejector seat, a rear bulletproof shield, forward machine guns concealed behind the headlights, rearward defenses including smoke and oil slick sprayers. All essential items for the late 60's spy on the run in his vintage car.
2. Attaché Case (From Russia With Love) - This might not seem appropriate for the modern spy attempting to operate undercover in a foreign country but in 1963 this was an essential item for the British businessman abroad. Of course Bond's case came equipped with a foldaway AR-7 sniper’s rifle, a knife, 50 gold sovereigns and a canister of teargas primed to explode if it was opened by anyone other than it's owner. Makes an off-screen, and humorous, reappearance in Goldfinger when Bond is told it has been "damaged" whilst being examined by Goldfinger's henchmen.
3. Rolex Oyster Submariner (Live & Let Die) - The Rolex Submariner is worn by Bond in a number of films, but stakes it's claim for gadget glory when it is returned to Bond at the start of "Live & Let Die" after being "repaired" by Q-Branch. The modified watch has a powerful electro-magnet that can (and I'm really not quite convinced about the science of this) deflect bullets and also a spinning bezel which is subsequently used by Bond to free himself from his rope restraints and escape the pool of man-eating sharks.
4. Sony Ericsson Mobile Phone (Tomorrow Never Dies) - Now THIS is a phone that can multi-task. Never mind your mega pixel camera or MP3 player (though it probably has those as well) this phone loads up with a spectacular array of useful tools. A stun gun, a fingerprint scanner, analyzer and transmitter that can also be used for opening high-tech fingerprint-identification locks, and a lock pick. As if that weren't enough it also houses a flip-open remote control for the control of his BMW 750iL. I've got a Sony Ericsson phone, I've not yet worked out how to access these functions.
5. Jet packs (Thunderball)- Thunderball saw the use of two different types of jet pack. The standard variety enables Bond to escape after killing SPECTRE agent Colonel Bouvar. Though slightly ungainly in execution the scene did provide an iconic moment in the film. Later he uses an underwater jet pack, equipped with explosive tipped spear guns as he attempts to capture Largo and fend off his henchmen.
More gadget related information here, here and here.