The International Python Conference (IPC) is held anually, in the U.S., more or less in the end of their winter. The biggest names in the community gather there and make talks; it's a great opportunity to meet people. In the past it was also used to make decisions about the future of Python, and there is talk of bringing this aspect back in the next conferences.
Next conference
The conference in 2002 (Python10) was professionally organized by a specialized company. It was way too expensive, many developers were not satisfied with some aspects, and it lost a lot of money (from the company's point of view).
Because of that, the conference in 2003 will be majorly revised. It is being discussed in a mailing list, and you can participate: http://mail.python.org/mailman/listinfo/conferences-discuss - or leave your comments in this page.
As of today (2002-Aug-31), chances are Python11 will either be a sub-event of one of O'Reilly's OSCONs, or it will be organized by volunteers with the expert help of [http://yetanother.org/ Yet Another Society] (who already helps with YAPC - "Yet Another Perl Conference" - and Mozilla Developer Days). Perhaps both will happen, and the YAS event will be titled "YAPyC" or something.
Past conferences
[http://www.python10.org Python10], the 10th International Python Conference, was held at February 4-7, 2002 in Alexandria, VA.
[http://www.python9.org Python9], the 9th International Python Conference, was held at March 2001 in Long Beach, CA
[http://python.org/workshops/2000-01/ Python8], the 8th International Python Conference, was held at January 2000 in Arlington, VA
[http://www.foretec.com/python/workshops/1998-11/ Python7], the 7th International Python Conference, was held at November 1998 at Houston, TX
[http://python.org/workshops/1997-10/ Python6], the 6th International Python Conference, was held at October 1997 in San Jose, CA
[http://python.org/workshops/1996-06/ Python5], the International Python Conference IV, was held at June 1996 in Livermore, CA