Is there an efficient way to exploit arbitrages between the different exchanges? The Bitcoin ratio vs other currencies is not the same among exchanges. Is there currently a way to exploit this arbitrage and profit?
Yes.  Simply hold accounts on multiple exchanges.  In the account you should try to keep your holdings at 50% bitcoin and 50% other currency.  

When there is an arbitrage opportunity you can execute "complimentary" transactions on both exchanges.  On one you buy the difference, and the other you sell the difference.  You can then equalize the accounts by transferring bitcoins between them, or withdrawing profits.  Don't forget to account for transaction fees on each exchange.

If you are so skilled most exchanges have APIs that would allow you to script interfaces for doing this automatically.  I recommend against accepting other people's scripts to do this since it gives the script access to your funds and it would be trivial for them to write the script to transfer your funds to them.