This is a reply to kireinaha's thread here https://bitcointalk.org/index.php?topic=341507.0 ... obviously I can't post there yet.

Arbing by moving fiat around carries huge risk due to the long bank-transfer delays & charges, during which prices could drastically change.

I've looked into arbing using altcoins for the moves, say between BTCE and Cryptsy.
E.g.
Buy BTC on BTCE
Move BTC to Cryptsy
Sell BTC into PPC say
Move PPC back to BTCE
Buy BTC again

But according to recent prices (last 3 days), it doesn't work out for either PPC or NMC.
I presume algos are doing it already?