Brian Solis on his PR2.0 blog has collated and published this amazing list of the top 100 ways you can use Twitter.

Twitter Client Market Share
1. Web,40.945%
2. API,11.6418% (custom applications, scripts or bots)
3. TweetDeck,6.635%
4. UberTwitter,4.288%
5. twitterfeed,3.9538%
6. txt,3.9254%
7. mobile web,3.567%
8. TwitterFon,2.4622%
9. Tweetie,2.1434%
10. TwitterFox,1.3588%
11. Echofon,1.3356%
12. Twitterrific,1.2322%
13. twidroid,0.886%
14. twhirl,0.8756%
15. movatwitter,0.8398%
16. TwitterBerry,0.835%
17. TwitPic,0.7806%
18. Seesmic,0.5524%
19. Tween,0.5414%
20. HootSuite,0.5258%
21. Power Twitter,0.3556%
22. Twit,0.3358%
23. gmedtwitpost,0.3188%
24. Snaptu,0.3018%
25. Twittelator,0.3%
26. POLLpigeon,0.2868%
27. FriendFeed,0.275%
28. P3:PeraPeraPrv,0.229%
29. DestroyTwitter,0.2188%
30. Perl Net::Twitter,0.2154%
31. Ping.fm,0.2128%
32. LOL quiz,0.1792%
33. TwitterGadget,0.1758%
34. Facebook,0.1722%
35. Twitter Tools,0.1558%
36. Tumblr,0.144%
37. RSS2Twitter,0.1412%
38. Sidekick,0.1386%
39. twitRobot,0.1338%
40. Google,0.1326%
41. dabr,0.1304%
42. CoTweet,0.129%
43. Blip.fm,0.1276%
44. Fun140,0.1274%
45. Gravity,0.1264%
46. SocialScope,0.1116%
47. Tweed,0.1074%
48. YoruFukurou,0.1064%
49. Mobile Tweete,0.106%
50. BlogTalkRadio,0.106%
51. WP to Twitter,0.1058%
52. bit.ly,0.0962%
53. iTweet,0.0914%
54. PockeTwit,0.091%
55. Tweetbots,0.0902%
56. PhotoShare,0.0862%
57. TwitterRide,0.0854%
58. NatsuLiphone,0.0794%
59. Mobster World,0.0784%
60. SimplyTweet,0.0672%
61. TinyTwitter,0.0664%
62. Digsby,0.0642%
63. Twitter4J,0.0614%
64. Reuters.com,0.0608%
65. Ustream,0.0606%
66. Tweets60,0.0584%
67. Movatter,0.0572%
68. MySpace,0.0568%
69. twibble,0.0562%
70. TwitZap,0.0526%
71. Twitter4R,0.0518%
72. Twaitter,0.0484%
73. Twitterizer,0.048%
74. Nambu,0.0464%
75. TwitterBar,0.0426%
76. Twikini,0.0412%
77. Epic Pet Wars,0.0386%
78. Twitme for WordPress,0.0368%
79. Photomemo,0.0356%
80. Mixero,0.0356%
81. yoono,0.0332%
82. Netvibes,0.0328%
83. TwitBin,0.0326%
84. Flock,0.0316%
85. Twidget,0.0312%
86. Spaz,0.031%
87. WordTwit,0.0308%
88. Twitterena,0.0304%
89. Post to Twitter,0.0298%
90. 140 Mafia,0.0298%
91. TweetSG,0.0292%
92. Fantasy Sports,0.0292%
93. Gwibber,0.0276%
94. TwiXtreme,0.0276%
95. Posterous,0.0274%
96. m.slandr.net,0.0272%
97. TwitKit,0.0264%
98. Twitter Opera widget,0.0264%
99. Tweet-U-Later,0.0264%
100. Twibbon,0.026%
101. Splitweet,0.026%
102. schuelerVZ,0.026%
103. ShareThis.com,0.0258%
104. TwitterMail,0.0256%
105. twittai,0.0252%
106. Identica,0.0236%
107. Adium,0.0228%
108. Brightkite,0.0224%
109. モバツイッター,0.0224%
110. Stickam,0.0218%
111. HTC Peep,0.0218%
112. BeTwittered,0.021%
113. TweetLeads,0.021%
114. Adjix,0.0208%
115. Twitstat Mobile,0.02%
116. TwitterIrcGateway,0.0198%
117. Viigo,0.0188%
118. EventBox,0.0186%
119. TweetGenius,0.0184%
120. twitthat,0.0184%
121. blu,0.017%
122. TwInbox,0.0168%
123. Matt,0.0166%
124. TweetPhoto,0.0166%
125. buzztap,0.0166%
126. TweetGrid,0.016%
127. Bird Feeder,0.0158%
128. JTwitter,0.0158%
129. LiveTweeter,0.0156%
130. TwitThis,0.0152%
131. TypePad,0.0152%
132. Spymaster,0.0152%
133. Flickr,0.0152%
Mind boggling really isn’t it? (More on that later…)

And what is the best one? Is it simply the one used by the most people? Obviously it depends on for what purpose you are using it for, those just keeping in touch with friends will have far different requirements than those actively monitoring their brand’s reputation.
However, I’d be interested to know if you have a favourite Twitter application you use all the time?
My personal experience is that I swap and change all the time between a few different applications, but having said that I’m not surprised really…. as a total aside (read: stop reading here if you are just interested in the Twitter story), someone asked me the other day which arm I put first into the armhole when putting on a jacket - apparently it has something to do with which side of your brain is dominant and makes a huge difference if you ever have a stroke - and, I realised I use both…but I’m still not sure what that means if I do have a stroke? Best not to think about that…
But it does reminds me of a really interesting little test we posted ages ago which determines which side of your brain you think with: Creative or Practical - here’s the link to the old post - have a go it is pretty cool. And yes, in case you were wondering she turns a different way everytime I look at her…now my mind is truly boggled.