bitcoin/bitcoin — pull request #2162 by gavinandresen (2013-01-09 19:11:01+00:00)
Title: spendfrom.py sends coins from a particular address or addresses

Should be both useful and also a pretty good demonstration of using the raw transactions API.

Test plan:
https://github.com/gavinandresen/QA/blob/master/SpendFrom.md

... reportedly run successfully:
https://bitcointalk.org/index.php?topic=135406.0