How much pain can I take?

[redneck one]

Cheap, dirty, and safe: 9V battery applied to the labia, tongue, or moist breast.

Large enema (not only painful (when held), but very humilitating)

Surface irritation to the nipples (or clit) (X number of strokes with a stiff brush)

Some people find a butt plug becomes very painful with time, others just find it irritating. Use menthol vasoline.

Alligator clips (from radio shack) or metal binder clips applied to the sensitive areas (inside upper arm besides the more erotic sites.)

Remove your pubic hair with needle nose pliers. Count each hair.

Canning yourself is possable (3/8 or 1/2" dowel from home depot)

Pepper sauce to the nipples or labia (work up on this one- the pain does not go away with washing)

There are some fun tricks involving holding your urine (either because of humiliation, or pain forom electric shock (ie wires in panties which don't make good contact until they get wet)), but I'm told you don't want to do this long term.

Thumbtacks in shoe (you can reduce penetration by poking them through with hard cardboard), with you either walking a long distance or forcing you to stand on your toes, both preferabally in public. A single marble works too, if you can hold it in place.

Wonder if sand in the bra or panties would work (combined with a long run or walk). It is hell on guys.

However, I suspect you could take a lot more if combined with some pleasure. But it would be fun watching you find your limit regardless.