Do you find yourself getting arrested a lot, under threat of kidnap, or do you merely need a way out of BDSM scenarios gone awry? If yes, chances are you need a titanium escape ring ($69).
Essentially, the outside looks like a normal ring. Concealed within, however, is a saw and a handcuff shim. A shim is a tool that can open most single-lock handcuffs (like so), and the saw will take care of those pesky but increasingly common zip ties, or any other tools common amongst kidnappers, like duct tape and rope.