Here's some pseudocode of how you would use the account based commands.  It sure makes website integration a lot easier.

print "send to " + getaccountaddress(username) + " to fund your account"
print "balance: " + getbalance(username, 0)
print "available balance: " + getbalance(username, 6)

// if you make a sale, move the money out of their account
move(username, "", amount, 6)

// withdrawal
sendfrom(username, bitcoinaddress, amount, 6)