bitcoin/bitcoin — pull request #989 by luke-jr (2012-03-26 14:39:33+00:00)
Title: New -minfee and -minfeeper options (with JSON-RPC setminfee to change at runtime) to control minimum fee requirements for transaction inclusion in blocks mined

This feature was requested and paid for by p2pool miner "DeathAndTaxes": https://bitcointalk.org/index.php?topic=73941.0