what do you mean "good"? pink sheets are complete baloney, mostly shell companies, otcbb can be traded at any brokerage I have ever heard of. Most otcbb's are baloney also except for very rare exceptions. Go to the dog track instead.
Used to be you could trade them at myTrack (www.mytrack.com). I think they were involved in something to make that marketplace more electronic, too. Don't know about shorting, though. That would seem to be a risk-management nightmare.
