FEB. 29 -- TUESDAY * Happy Leap Day! This is the first leap day in a year ending in -00 since 1600, nine years before Galileo used his first telescope.

This page gives a basic explanation of leap year: http://www.digtl.com/leapyr.htm

Here's a slightly different version from the Royal Observatory Greenwich: http://www.rog.nmm.ac.uk/leaflets/leapyear/leapyear.html

This one includes information that not everybody added 10 days in 1582, that was the Catholics.

Britain and its colonies didn't change until 1752 and then went from September 2nd to Sept 14th, adding 11 days.

Did you know that there are also Leap Seconds added to many years? Here is a rather complicated explanation from the US Naval Observatory: http://tycho.usno.navy.mil/leapsec.html

Were you born on Leap Day? Did you know that there is an Honor Society of Leap Day Babies? http://www.leapdaybabies.com/

There is even a Leap Year Capital of the World - Anthony, New Mexico/Texas USA. They are going to have one heck of a bash there this year. Here's a snip from the site: "The Leap Year 2000 Festival will include a Leap Year Day Parade, Hot Air Balloon lift off, Chuck Wagon Breakfast, hayrides, Antique Tractor Show, golf tournament, Hunch (Washer) Tournament, tours of the valley, Golden Oldies 'Big Band of the Rio Grande' Concert and dance, Square Dancing, 10K Run, 2 mile walk, carnival, petting zoo, juried Arts and Crafts Festival, International Food Booths, fireworks, and, of course, the biggest Worldwide Leap Year Birthday Party ever held. In addition, a special feature will be a personal concert by Graham Nash of "Crosby, Stills and Nash."
http://www.zianet.com/snm/leapyear.htm

This one has some articles and explanations and links: http://www.emailman.com/leapday/index.html