@nmat, if i import the key pair you generated and charged with funds into my wallet and set it on auto, make a transaction to transfer funds on one of my personal accounts, how would you double spend the coins without having some superhero abilities of some kind ?
Finney attackI don't need superhero abilities, just a decent amount of computational power
It is obviously not simple and
may not be practical to do, but if you are relying on this "instant transaction" to make large deals (several thousands of dollars) you may be defrauded. You need to wait for confirmations on the transaction to your personal account.
EDIT: The general idea of the attack is that I am pre-mining blocks which include the transaction from my address A to my address B, but I don't release them. Then I give you the private key/wallet to my address A. You give me the money and send a transaction from the address A (which you now control) to your address C. As soon as I "hear" your transaction spending the coins in A, I release the block with a transaction from A to B, which invalidates your transaction.
i would happily wait an hour if it's a really large sum, invite the other person a coffee, take a walk or something else. we could turn more social using this system, you never know