Found this @ Ratdog.org- I've read it before, for those who havent, Here goes:
You know you're a Deadhead when...''
(the exhaustive list)

1. You spend more money on blank tapes than you do on rent.

2. None of your tapes have names on them, just dates.

3. You have over 50,000 lines of Email received by your account every month.

4. You swear the guy walking by you at the company softball game just said ''doses.''

5. You prefix every noun with ''Kind'', or ''Ice cold''.

6. You spend more money at the post office than at the gas station.

7. You still have the parking tag from NYE 1976 hanging from your rear view mirror.

8. On forms you list your occupation as ''?''.

9. GDTRFB, SSDD, BIODTL, FOTD, SOTM, LTGTR, NFA, and WALSTIB all mean something to you.

10. At any given moment you can compute how many days, hours, minutes, and seconds it's been since ALLIGATOR has been played.

11. Someone asks you what you do for fun, and you just smile real wide.

12. The first entry on your MCI Friend's and Family list is 415-457-6388.

13. You got #12.

14. You try to tell your Russian History prof. that Marx stole the phrase ''One man gathers what another man spills'' from Robert Hunter.

15. You think $1 for a grilled cheese sandwich is pretty damn cheap.

16. You're up at 3:20 am writing some stupid ''Know you're a deadhead when...'' list instead of sleeping.

17. You're boss notice members of you're family only become deathly ill when their happens to be a deadshow within a 1000 mile radius.

18. Your Windows background is a picture of Jerry Garcia, your cursor is a Steal Your Face skull, and sometimes you swear it's leaving ''trails''.

19. The mainframe sysop wants to know how the 400 page file entitled ''Lyrics to 300 Grateful Dead Songs'' that you sent to the new laser printer relates to the CS 465 project you've been working on.

20. Whenever you walk through a parking lot you instinctively hold your right index finger in the air.

21. The compass in your car is calibrated so that it always points to the Oakland Coliseum.

22. You can install a new cylinder head on a '68 VW microbus with your eyes closed.

23. You have more tie-dyes than neck-ties.

24. You find it amazing that some people fill balloons with AIR.

25. You try to convince your grandmother Aoxomoxoa is an acceptable play for a Scrabble triple word score.

26. Your dog is named Bertha.

27. Your KID is named Althea.

28. You spend New Year's Eve with your cassette deck instead of your wife.

29. You're license plate spells ''HEY NOW''.

30. You've learned to DUCK.

31. You wonder if Dupree's Diamond News is going to have a swimsuit issue this year. (WARNING Thinking about this one may ruin your appetite.)

32. Your stock portfolio includes 50 shares of the HANES BLACK T-Shirt division

33. You consider a ''Miracle'' to be a ticket to tonight's show.

34. You can't leave the house without wondering where the tickets are.

35. Left unoccupied your hand instinctively taps the beat to Not Fade Away.

36. You actually are in search of the Eternal Buzz.

37. You're still waiting for that second verse of the Dark Star that they started back in May of '73.

38. You still wonder what the lyrics to The Night They Drove Ole Dixie Down are

39. You consider ;-) a new form of punctuation.

40. You sign up for the 9/10/91 tree and offer to make 2500 copies, and then completely forget you're on it.

41. There are 10 people still shacking up at your house from the summer 1990 tour, and you don't know any of them.

42. You consider veggie burritos gourmet.

43. You know the words to Truckin' better than Bob. (OK, I guess this doesn't necessarily mean your a deadHEAD...)

44. You can remember an Other One that wasn't followed by Wharf Rat, or a Throwing Stones that wasn't followed by Not Fade Away.

45. You try to claim gas to and from Dead shows as an income tax deduction.

46. You know the Zip code for San Rafael, CA by heart.

47. You have the postal rates memorized.

48. Your copy of Deadbase has long since broken out of it's binding and the ink is beginning to wear off the pages.

49. You spend all morning looking for this killer Playin' Jam that you think is on this tape from '72, probably the Fillmore, and you know it's a Maxell with the label on upside down, but it doesn't have a case, and you know the tape starts with Sugaree but the last time you think you saw it was in '83 and it was under your friend Brian's refrigerator, or maybe it was just a filler on that Alpine Valley '89 show, which you think you probably listened to in that dude's bus on the way to Deer Creek this year, but his phone number is on the back of the ticket stub that you think is stuffed in your Soundboard copy of 7/8/78 set II, and you have NO idea where that is, so you pull out Deadbase and start looking through every show since '71 that even had a Playin' but by '77 or so you forgot what you were looking for because you got wrapped up in the Nice version of He's Gone where Mickey starts playing the beam with dead cat, etc. etc. (If this sounds like something that happens to you every day, you know you're a deadhead.)

50. You swear the guy walking by you at the football game just said ''doses''.

51. You're beginning to wonder if Bob's ever going to retire that Tamalpais Chiefs shirt.

52. You've figured out the correlation between the date and the # of beats to start BIODTL.

53. You know how ''the song'' goes...

54. Your car windows look like stained glass from being covered with coloured stickers.

55. The bus came by, and you got on.

56. Lately, It occurs to you just exactly What A Long Strange Trip It Has Been... =)