Taylor Hotner
When: August 10
What: The Twilight Saga's sexy werewolf
Why: George Lopez, who was cleverly disguised as the fourth Kardashian sister, coined the catchy nickname for Taylor Lautner at the Teen Choice Awards. Oh yeah, and he won the night's Choice Hottie award too. (Taylor, not George.)
Pretty Little Liars Marathon
When: August 10
What: ABC Family's series about pretty girls and their ugly secrets
Why: Tuesday was the season finale for the breakout hit, and naturally, every episode thus far was aired. Hence, Tweet excitement. When will we know who A is, darnit?
Joanne Kathleen Rowling
When: 7/29
What: The Harry Potter author's full name
Why: There's no real reason, other than she has a dedicated fanbase that loves to tweet about her on just a regular old Thursday.
Thor
When: 7/29
What: Superhero movie about a guy with a hammer
Why: A five minute extended trailer for the movie was released, so all the fanboys tweeted their reactions, natch.
Smashing Pumpkins
When: 7/28
What: Only one of the most well known bands of all time
Why: All Twitter Trending Topic bets were off when front man Billy Corgan announced the band would be performing in Sao Paulo, Brazil later this year, sending Brazil into a Twittering frenzy.
Inception
When: 7/27
What: If you don't know what Inception is at this point, you have been living under a rock
Why: Seriously, people cannot stop tweeting about this movie. If it keeps up this momentum, they're going to have to change the algorithm, or whatever it was they did so that Justin Bieber couldn't be a trending topic any more.
Pretty Little Liars
When: July 27
What: ABC Family's hot summer series about pretty girls with ugly secrets
Why: The breakout hit airs on Tuesdays, so every one felt the need to tweet their excitement for the show.
#4millionbeliebers/Bustin Drew Jieber
When: July 26
What: Justin Bieber's army of beliebers, obviously
Why: You can't keep Justin Bieber's fans down. Even though the bigwigs at Twitter did some major tweaking to keep Justin out the trending topics, his fans found a way to show their neverending love.
Lindsey Lohan (yes, with an "e")
When: July 20
What: Actress turned jailbird
Why: July 20 was the big day Lindsay had to turn herself in for her 90-day sentence in the clink. You'd think all the coverage she gets in the press, people would be able to spell her name right. But no. Sadface.
DIUSTIN BIBER
When: July 23
What: An alternate name for Justin Bieber.
Why: Fans are creative when it comes to getting around Twitter's trending topics algorithm and getting their guy back on top.
#happybirthdayselena
When: July 22
What: Selena Gomez's birthday
Why: The Disney darling hit the big 1-8 on July 22 and hoards of Tweet-ers decided to wish the cutie a Happy Birthday.
Sylvester Stallone
When: July 23
Who: The Expendables action star
Why: Comments he made about Brazil at Comic-Con upset several people. He said he shot The Expendables there because, "you can kill people and blow the whole country up and they'll say thank you, and give you a monkey." The trending topic eventually evolved into "CALA BOCA SYLVESTER STALLONE" which means shut up in Portugese.
Tron
When: July 22
What: Highly anticipated Disney sequel
Why: People have been buzzing about this release for what seems like forever and the Twitter world was all, well, atwitter about its panel at Comic-Con.
Comic-Con
When: July 21-23
What: Convention in San Diego about all things awesome
Why: Nerds unite! Every year the masses head down to San Diego to get dish on movies, television and more.
Inception (Part Deux)
When: July 19-23
What: Christopher Nolan's mind-bending (and lucrative) thriller
Why: Well, it was kinda the best and everyone just keeps talking about it.
United4Miley2Years
When: July 19
What: Miley Cyrus, duh
Why: Twitter loves Miley and sometimes that love is all channeled into one trending topic.
Omaha Mall
When: July 16
What: Just a regular old mall in Omaha, Neb.
Why: It always comes back to Bieber. Justin has a rap about the Omaha Mall and his fans love it, obviously.
Keep clicking for more of Twitter's biggest trending topics...
Ryan Reynolds
When: July 15
What: The sexy action star
Why: After the first look of Ryan portraying superhero The Green Lantern hit the web, the Twitterverse went crazy with excitement.
Inception
When: July 14-16
What: The sure-to-be-summer-blockbuster starring Leonardo DiCaprio
Why: Since this summer movie season has been the most boring in who knows how long, people were buzzing early about the July 16 release, which is but a small beacon of hope for us summer movie faithfuls.

