Woah... That's a pretty unique sig you have there.
Well bristles come off of those nifty little cleaning machines that you've probably seen driving around your area. The bristles that they use to sweep the roads are made of metal (Well if you're lucky at any rate) and routinely snap off when they brush against the curb. Stalk one of these machines and follow its route. If you are lucky some might fall off as you follow; if they don't then check back in a few days.
Alternatives include:
*Bent nails, flattened at the end
*Bicycle spokes bent to a 90 degree bend, and with the end flattened
*Allen keys that have been ground down (expensive though)
*Wiper blade inserts as suggested by Anero - the best material and it makes great wrenches IMHO
*The metal clips from some pens will work with a measure of success
*Paper-clips... They work to an extent, but there are far better materials
*Kitchen forks - Yeah, they do work...
*Safety pins - SFGOON mentioned using them as feather touch wrenches
*Pretty much any piece of fairly stiff material that has a 90 degree bend in it, and is small enough not to impede the picking procedure
Hope this helps.
