You have your body -- Voice, Elbow, Palm, Foot, Teeth, Fingers/Nails, Knee and Head
Voice - Yell
Use it as something to swing at the attacker
Snap off the eraser and sharpen both ends. Ready to use, bring with you everywhere. Lift up once to eyes/face, down to hand, leg, etc.
Threaten to shoot attacker. YOU NEED CONCEALED WEAPONS PERMIT FOR THIS.
Stun Gun / Taser
Threaten to stun attacker. State-specific laws listed here.
Pepper Spray / Mace
Threaten to spray attacker. Not always potent enough.
Knife / Switchblade
Threaten to stab attacker.
Packages / Purse / Items In Hand
Projectiles readily available to hurl at attacker.
Canned Item in a Grocery Bag
Ready to swing at attacker.
Rake across the face of attacker