I have a question concerning the transaction of bitcoins. If, for example, I send some BTC to a specific address, does the receiver have any chance in verifying that I have already sent the BTC, before they are being registered in his wallet? I know there is http://blockexplorer.com/, where I can look the transactions up. But is there any functionality for it in the Bitcoin-Client, which I could use in RPC-Calls?
Use case for this: Assume there is an application that uses Bitcoin via RPC-Calls to the Client. I want to buy something via the application and the seller should be able to see that I paid the correct amount of BTC without having to wait for the transaction to be finally redeemed in his client.
Thanks in advance!