I don't think arbitrage has to be in USD for you to make a profit on the trading concept. For instance, take a look at bitcoinwisdom and see the price differences in BTC and LTC between the exchanges - the differences are quite noticeable.

Here's an arbitrage example that I plan on doing: 
1. Buy BTC at Coinbase and move it to BTC-E.
2. At BTC-E, swap your BTC with LTC
3. Move LTC to another exchange like Crypto-Trade
4. At Cryto-Trade, swap LTC back to BTC
5. Move BTC back to BTC-E and repeat.

The goal is to slowly grow my BTC count, and then move back to Coinbase to cash out.

While I do this, I will be familiarizing myself with the commission fees and transfer fees for each exchange and calculate those fees into my equation. I'll also keep close attention to news at bitcointalk and coindesk about any troubles the exchanges might be having.

-BeaconDelta



 

Interesting phenomenon happening right now - no one I've asked seems to know why there's low trading volume in the exchanges since last weekend. BTC-E had a whopping 0.004 bitcoins traded in the past 15 minutes (Jan 18, 4pm E.S.T.) - really unusual to have so little activity on a Saturday afternoon like this. Trollbox activity very low as well - many of the frequent posters from months ago are absent.

Any ideas regarding what's going on?

--BeaconDelta

I found the safest and most reputable entry point into the bitcoin world is through bank --> Dwolla --> CampBX.  You have to get through the first 31 day evaluation period of course, but I think it's worth the wait. During that period, you can buy/sell btc with in the CampBX exchange, you just can't withdraw until after the first 31 days. I had a great experience getting started with this method - I learned quickly how to do limit sell/buys, dark pool orders. They also offer margin. Good experience. I recommend it.