Trying to think of my last lesiure trips:

Upcoming September '04 trip to SFO: flight booked in March, hotel booked in June
June 04 trip to East Coast US: flight booked 2 weeks before
April 04 trip to East Coast US: flight booked 5 weeks out
February 04 trip to East Coast US: flight booked 3 weeks out
December 03 trip to East Coast US: flight booked in September 03
September 03 trip to Washington DC: all booked in March
August 03 trip to Berlin: booked 3 weeks before hand