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. Leapalicious- Something that is good

3. Leaparium - A chat room for Leapeans

4. 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!

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

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

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

8. LeapChik - A female born on Leap Day.

9. LeapCouple - Two Leapies married to each other

10. LeapDad - Father of a Leap Day baby

11. Leapdom - www.leapyearday.com

12. LeapDude - A male born on Leap Day.

13. Leapeans - People born on Leap Day

14. Leaper - A person born on Leap Day

15. 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."

16. Leapest Regards - Deeper than Deepest Regards

17. Leapette - Female Leapean

18. Leapfully - As in Respectfully

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

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

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

22. Leapically - As in Leapically correct

23. Leapicious - Something that is good

24. Leapidemic - An epidemic (needs more explanation)

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

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

27. Leapified

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

29. Leapination - What in Leapination is that?

30. Leapingly - As in Sincerely

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

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

33. Leapist - Someone really into their Leapness

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

35. Leapless - Anyone not born on February 29.

36. Leapling - A newborn Leap Day baby

37. LeapMom - Mother of a Leap Day baby

38. Leapness - Regarding the essence of our birthday

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

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

41. Leapometer says this website is highly Leapified.

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

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

44. Leaprechaun - An Irish Leaper

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

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

47. Leapster - Male or female Leap Day baby.

48. Leaptacular - As in spectacular

49. Leaptastic - An amazing Leap Year related thing.

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

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