Second of all- just like BitPay immediately sells the BTC you send them on the open market, when you pay for something using BTC, why not build some sort of "Meta" payment processor: something that immediately sells your LTC for BTC and then enters the BTC into Bitpay processing? Bitpay locks your exchange rate for 15 minutes when you purchase- more then enough time for an intermediary to sell LTC for BTC.
That said- we need more LTC exchanges so the market gets more depth.
How does more exchanges give more depth?
All more exchanges does is spread the depth thinner across more sites - leading to very shallow order books everywhere and an exchange-rate that fluctuates even more wildly due to increased arbitragin opportunities.
The way to get more depth (And more stability) is to have more uses for LTC - it's really that simple. Right now the exchange-rate is set long-term by whim and short-term by bots(mainly) and traders arbitraging across LTC/BTC and LTC/USD to correct imbalances caused by changes in the BTC/USD market. Meaningful stability is still a long way off even for BTC - let alone LTC -as nothing of note is priced in BTC (price is set in fiat then converted temporarily to BTC for the transaction).
I'm not AGAINST more exchanges - but increased depth isn't what they'd provide (other than if they're in a currency not support yet - in which case it isn't more depth it's new depth in a new market).
Yes, more exchanges doesn't help. In fact, it would appear to make things worse (or at least more complex).