I can only suggest the kind of store, not one in particular since I am not in Orange CA Look for hobby stores, particularly those that cater to model airplanes, radio controlled cars and airplanes, etc. That\'s where I found mine. Another possibility is micromark (www.micromark.com), they have all kinds of hobby related goodies, and I believe they also have tiny drill bits. Keep in mind though you are likely to have to buy a set of them, though perhaps you might be able to buy a bunch of them of the same size... but its more likely they will only be offered in like a set of multiple sized bits...
--Katie G.
Even some crappy hobby shops have different sets of pin vices and bits. Even hardware stores have pins you could use, rotary tool bits work well, but most are made made for high speed spinnin\'.