Out friends over at PetLvr.com posted a great entry on their blog detailing the Pet Emergency Kit that most families with pets should have on hand.  They suggest having two kits, one for the home and another for the car.  Some of the  items to include:

• 4 Rolls of Gauze – For bandaging wounds and creating splints.
• 1 Box of Large Gauze Pads – For absorbing blood. You’ll put these directly on the wound and then wrap the rolled gauze around the gauze pads.
• 1 Travel Size Pack of Cotton Swabs – For applying antibiotic ointment or cleaning a wound.
• 2 Ace Bandages – For creating splints or applying a pressure wrap on a bleeding limb.
• 1 Bottle of Betadine – For disinfecting wounds (no sting) and preventing infection.
• 2 Bottles of Wound Wash Saline – For flushing puncture wounds or flushing wounds near the eyes. Wound wash saline is also helpful in removing debris from a wound when you’re away from home.
• 2 Instant Cold Packs – For reducing swelling associated with an injury or wound.
• 1 Large Blanket – For warming an animal who’s been exposed to cold. You’ll also want to keep a dog warm if he’s sustained serious injuries and is on the verge of going into shock. A large blanket can also be used as a stretcher for a pet. You can also throw the blanket over an injured animal to catch it or to protect yourself while putting the injured animal into a carrier or box.
• 1 Small Blanket – You never know when you may need a smaller blanket too! You can use it as a makeshift bandage, you can tear a strip to create a muzzle – they’re good for just about any emergency situation you encounter.
• 1 Pair of Tweezers – For removing a tick, or removing debris from a wound.

That is a pretty good start, and I do not think even Dr. House would disagree.