I really appreciate the good work Bitstamp is doing but this trading without option of stop loss order is unacceptable! For some people Bitcoin is their first and only commodity they're invested in, the risk of losing their investment overnight is actually what stops them from believing in this new currency and eventually makes the market so volatile. Offering stop loss order would bring a lot of clarity and stability to the exchange and overall Bitcoin value. Please, get your best and brightest working on it.
For a kick off, stop loss orders are most useful for
leveraged investments like futures, options, CFDs, spread bets.
Secondly, you can't go short on Bitstamp, so the only panic exit you can take is to sell when the market is falling. Well, at 1:1 if you can't afford to take a (probably temporary) loss on your BTC investment then DON'T BUY in the first place.
BTC is the strongest currency in the world. If you are going to panic while owning some - then stay out and watch. Meanwhile your fiat is being eroded in real-terms. That is the real risk.