Listed here are some words the Oxford English Dictionary missed.
If it's in the New York Times, it must be a word!
New York Times 24/Feb/00 headline proclaims:
Sites Help Leaplings Bridge Birthday Gap.
The story also features the usage of Leaptionary and Leapest.
 

1. Leapabilly - Any music with a Leap Year Day reference.

2. Leapability - the ability of a Leap Day person to achieve something

3. Leapalicious- Something that is good

4. Leaparium - A chat room for Leapeans

5. Leapathon - a way of looking for Leapies; like having a Leapathon on the radio or TV announcing the search for people born on February 29. Encourage your city to have a Leapathon!

6. LeapBrother or LeapBro - Male Leap Day baby friends.

7. LeapCentral - www.leapyearday.com, and Raenell's office!

8. Leapcentric - One who collects Leap Year-themed items and products.

9. LeapChik - A female born on Leap Day.

10. LeapCouple - Two Leapies married to each other

11. LeapDad - Father of a Leap Day baby

12. Leapdom - www.leapyearday.com

13. LeapDude - A male born on Leap Day.

14. Leapeans - People born on Leap Day

15. Leaper - A person born on Leap Day

16. Leapery - This could be where a Leap Day baby hangs out or lives. It could also be where Leap Day babies are born. "Leaplings are born in the Leapery."

17. Leapest Regards - Deeper than Deepest Regards

18. Leapette - Female Leapean

19. Leapfully - As in Respectfully

20. LeapGram - The Grand Mother of a Leap Day baby

21. LeapGramp - The Grand Father of a Leap Day baby

22. Leapical - Something typical a Leap Day born may say or do.

23. Leapically - As in Leapically correct

24. Leapicious - Something that is good

25. Leapidemic - An epidemic (needs more explanation)

26. Leapier -  Something done by a Leapy is Leapier than that same something done by a non-Leapy.

27. Leapification - what happens to those born on Leap Day

28. Leapified

29. Leapify - To make Leap Day oriented. A person can be Leapified if they support Leap Day.

30. Leapination - What in Leapination is that?

31. Leapingly - As in Sincerely

32. Leapio! - Like Ciao or Aloha or Goodbye, See Ya, Leapio!

33. Leapism - A Leapified word or saying. But what else can it mean?

34. Leapist - Someone really into their Leapness

35. Leapitude - The attitude of a Leap Day Baby about their Leapness

36. Leapless - Anyone not born on February 29.

37. Leapling - A newborn Leap Day baby

38. LeapMom - Mother of a Leap Day baby

39. Leapness - Regarding the essence of our birthday

40. Leap On! - It's like saying Right On!

41. Leapometer - How to tell if something is Leapy enough.

42. Leapometer says this website is highly Leapified.

43. Leapover - A sleepover birthday party for a Leap Day baby.

44. LeapPeep - A friend who is born on Leap Day

45. Leaprechaun - An Irish Leaper

46. Leapship - A friendship or relationship between 2 Leapies.

47. LeapSister or LeapSis - Two female Leap Day baby friends

48. Leapster - Male or female Leap Day baby.

49. Leaptacular - As in spectacular

50. Leaptastic - An amazing Leap Year related thing.

51. Leap Twins - Someone born the same year and as close to the same time as possible

52. Leapy - Another word for a Leap Day baby.