For some people flying over the millennium is unavoidable, especially in the business sector. If you are flying:
Only use airlines and airports that are known to be Y2K compliant
Be prepared for delays. The industry says that delays will be at their worst on January 1st and 2nd but will improve as days go by.
Take plenty of cash on your trip, as ATM machines may malfunction - everywhere.
If possible take only hand baggage, checked-in baggage is at the mercy of a computer chip.
Find out from your airline or your tour operator what arrangements are in place if you are stranded abroad due to airports being closed and/or flights being cancelled.