Currency locking can be a bit tricky. Especially since any exchanges tend to either fold or lag when the DDOS's hit. Depending on how brave your team is using MPEX futures either through MPEX.co itself or Coin.br could maybe do quite a bit to mitigate your foreign exchange risk. There are other avenues for hedging, but a lot of them are built on broken and recycled code. Anywhere you might decide to hedge the FX risk is going to be iffy, but of all the futures options available at this time MPEX's seem the most solid (disclaimer: I am not a licensed broker, attorney, or agent of any sort). Not hedging and just holding extra coin you can't immediately unload at cost on the other hand to sell later might just be viable if you have the capital on reserve to wait before converting back to dollars.
If we offer the currency lock, it would be offered during checkout so the time window would be small. For example, during checkout, suppose a customer has a $22 order with a $4 tip. We would quote per the current exchange rate, 0.20635BTC at the moment, if paid within the next 5 minutes. Since we accept 0-confirmation deposits, this should be plenty of time for the customer to open their wallet and initiate the transfer. We'd bear the currency exposure risk, as we do today. It works in both directions so it ought to average out.
MPEX.co is interesting. They should position themselves as an alternative exchange for companies considering a smaller, less complicated IPO than traditional markets. The market depth isn't there right now, but it has to start somewhere.
Cool, so hedging should be less important then. MPEX options and hedging can be something of a hassle if you don't need it.