Don't forget that your'e paying twice as many fees if you're converting twice.
0.2% LTC/BTC(btc-e.com) fee + 0.001BTC (btc-e.com) withdrawal + 0.6% BTC/USD(mtgox.com) fee
1000LTC is 2LTC fee = $5
0.001 withdrawal = ~90c
0.6% mtgox fee = $15
under $25 in fee's for over $200 in my original example.
but yes that was all just an example of a trade that
could yield $175(after fee's) more dollars. and it is advisable you do watch out for the fee's