The service has very quickly become a very easy, cheap way for celebrities to have their ego stroked so they can bask in the glory of their popularity. Some people are brilliant (Richard Bacon, Adam Woodyatt, Boris Johnson) but the majority are complete and utter self-obsessed wankers. Yes you, Ashton Kutcher.

Twitter is supposed to be interactive; the very nature of its success is based on one person talking to another. What it is not is a forum for celebrities to use as a ready-made fan site.

So we wondered, who are the worst? Which celebrities are the most narcissistic? In order to find out I asked someone cleverer than me at HM HQ to come up with an equation which would immediately let us know if the celeb is a tool or not. The equation is thus:

100-(100 divided by f1 multiplied by f2)=tool percentage when: f1=followers f2=following

It's quite simple - the bigger the gap between followers and following, the higher the percentage. Are you still with us? Good!

Here is the current Top 40:

1. Russell Brand
2. Katy Perry
3. Lily Allen
4. Ashton Kutcher
5. Chris Moyles
6. Fred Durst
7. Demi Moore
8. Holly Willoughby
9. Fearne Cotton
10. Jamie Oliver
11. P Diddy
12. Perez Hilton
13. Andi Peters
14. Ryan Seacrest
15. Eddie Izzard
16. Charlie Brooker
17. Graham Norton
18. Paul Daniels
19. Richard Bacon
20. Matthew Horne
21. Solange Knowles
22. Matt Lucas
23. Alex Zane
24. Calvin Harris
25. Katie Price
26. Justin Lee Collins
27. Graham Coxon
28. Coldplay
29. Greg Wallace
30. Phillip Schofield
31. Peter Andre
32. Bille Piper
33. Adam Woodyatt
34. Jonathan Ross
35. Phil Jupitus
36. Jimmy Carr
37. Mike Skinner
38. Richard Branson
39. Britney Spears
40. Stephen Fry