Twitter's 2011 Year in review

In 2011, Twitter hit 100 million active users. See who joined.

January

11

Joaquin Lopez-Dóriga @lopezdoriga1

28

James Cameron @JimCameron

February

3

Howard Stern @HowardStern

5

Matt Drudge @DRUDGE

March

1

Charlie Sheen @CharlieSheen

21

Robin Roberts @RobinRoberts

22

Cristina Aguilera @TheRealXtina

28

Bronx Zoo's Cobra @BronxZoosCobra

29

Amtrak Northeast Corridor @AmtrakNEC

April

14

Billy Crystal @BillyCrystal

14

Nelson Mandela @NelsonMandela

May

9

U.S. Secret Service @SecretService

10

Jacob G. Zuma @SAPresident

25

Roberto Gomez Bolanos @ChespiritoRGB

27

Alec Baldwin @AlecBaldwin

June

1

Gwyneth Paltrow @GwynethPaltrow

1

Hope Solo @HopeSolo

5

Plaxico Burress @plaxico

9

Jill Abramson @JillAbramson

24

Dr. Willy Mutunga @WMutunga

29

The Pope @news_va_en

July

15

Jerry Seinfeld @JerrySeinfeld

16

Abby Wambach @AbbyWambach

19

Pharrell Williams @Pharrell

27

Mia Hamm @MiaHamm

29

Rafael Correa @MashiRafael

29

Rafael Nadal @RafaelNadal

29

Lewis Black @TheLewisBlack

August

30

Cheryl Cole @CherylCole

September

14

Jang Geun Suk @AsiaPrince_JKS

14

Salman Rushdie @SalmanRushdie

14

Juan Gabriel @1esJuanGabriel

16

Alan Partridge @ThisisPartridge

21

Melinda Gates @melindagates

29

House of Lords @UKHouseofLords

30

Ricky Gervais @rickygervais

October

3

Sean Parker @sparker

9

Gary Barlow @GBarlowOfficial

11

Samuel L. Jackson @SamuelLJackson

12

Condoleezza Rice @CondoleezzaRice

12

Eva Mendes @evamendes

November

16

Simon Cowell @SimonCowell