Ahhh, carabiners. never go anywhere without them.

Actually, all the gear I own (being a poor college student and all) is homemade. With two key rings and some sturdy wire cutters, two dog chains and a luggage lock become fine, sturdy cuffs that double as bracelets when you remove the lock... My favorite invention thus far.

2 dog chains = $2.00
1 luggage lock = $3.00
a night spent cuffed to the headboard = Priceless.