Recent speculation about MtGox has raised the possibility that Karpeles may have spent BTC into wallets for which he had invalid private keys.  Ie, his key generation algorithm may have malfunctioned.

I don't care to speculate about that.  However, it does raise a valid technical question...

Is there a way to test the private key of a Bitcoin wallet without transferring real value?  Ie, can I make a spend of 0.00000000 BTC to another wallet?

Obviously no value would xfer, but the transaction would get recorded in the blockchain.

Tell me, is this possible or practical as a way of doing a simple live test on a new wallet before sending live value to it?