(Of course, Twitter hasn’t revealed the secret formulas that helped it aggregate, tabulate and rank these topics.)

In the Twitterverse, after the BP oil spill and soccer, the next most popular topic of conversation in 2010 was the movie “Inception,” followed by the Haiti earthquake and the vuvuzela. The iPad, Android, Justin Bieber, Harry Potter and Pulpo Paul round out the top 10. It’s an odd list, indeed.

The person most discussed on Twitter in 2010 was obviously he of the dedicated servers, Mr. Bieber. (It’s somewhat shocking that world events and tech gadgets were able to keep the teen phenom out of the overall top spot.) Beating out her royal highness Lady Gaga, the No. 2 person on Twitter was Brazilian president-elect Dilma Rousseff (pictured).

Here’s the full 2010 list, courtesy of Twitter, followed by 2009′s list for comparison.

2010 Twitter Trends

Overall Top Trends:
1. Gulf Oil Spill
2. FIFA World Cup
3. Inception
4. Haiti Earthquake
5. Vuvuzela
6. Apple iPad
7. Google Android
8. Justin Bieber
9. Harry Potter and the Deathly Hallows
10. Pulpo Paul

News Events:
1. Gulf Oil Spill
2. Haiti Earthquake
3. Pakistan Floods
4. Koreas Conflict
5. Chilean Miners Rescue

People:
1. Justin Bieber
2. Dilma Rousseff
3. Lady Gaga
4. Julian Assange
5. Mel Gibson

Movies:
1. Inception
2. Harry Potter and the Deathly Hallows
3. Scott Pilgrim vs. the World
4. Despicable Me
5. Karate Kid

Television:
1. MTV Video Music Awards
2. Pretty Little Liars
3. True Blood
4. Walking Dead
5. Grammy Awards

Technology:
1. Apple iPad
2. Google Android
3. Apple iOS
4. Apple iPhone
5. Call of Duty: Black Ops

World Cup:
1. FIFA World Cup
2. Vuvuzela
3. Pulpo Paul
4. Dunga
5. Diego Maradona

Sports:
1. LeBron James
2. Wimbledon
3. Manchester United
4. Brock Lesnar
5. Celtics

Hash Tags:
1. #rememberwhen
2. #slapyourself
3. #confessiontime (hash tag started by Usher)
4. #thingsimiss
5. #ohjustlikeme

2009 Twitter Trends

News Events:
1. #iranelection
2. Swine Flu
3. Gaza
4. Iran
5. Tehran
6. #swineflu
7. AIG
8. #uksnow
9. Earth Hour
10. #inaug09

People:
1. Michael Jackson
2. Susan Boyle
3. Adam Lambert
4. Kobe (Bryant)
5. Chris Brown
6. Chuck Norris
7. Joe Wilson
8. Tiger Woods
9. Christian Bale
10. A-Rod (Alex Rodriguez)

Movies:
1. Harry Potter
2. New Moon
3. District 9
4. Paranormal Activity
5. Star Trek
6. True Blood
7. Transformers 2
8. Watchmen
9. Slumdog Millionaire
10. G.I. Joe

TV Shows:
1. American Idol
2. Glee
3. Teen Choice Awards
4. SNL (Saturday Night Live)
5. Dollhouse
6. Grey’s Anatomy
7. VMAS (Video Music Awards)
8. #bsg (Battlestar Galatica)
9. BET Awards
10. Lost

Sports (Teams, Events, Leagues):
1. Super Bowl
2. Lakers
3. Wimbledon
4. Cavs (Cleveland Cavaliers)
5. Superbowl
6. Chelsea
7. NFL
8. UFC 100
9. Yankees
10. Liverpool

Technology:
1. Google Wave
2. Snow Leopard
3. Tweetdeck
4. Windows 7
5. CES
6. Palm Pre
7. Google Latitude
8. #E3
9. #amazonfail
10. Macworld

Hash Tags:
1. #musicmonday
2. #iranelection
3. #sxsw
4. #swineflu
5. #nevertrust
6. #mm
7. #rememberwhen
8. #3drunkwords
9. #unacceptable
10. #iwish

Their loss. For the rest of us, hash tags–that is, sticking a “#” sign before a phrase in your Twitter message–have become an entertaining and useful way to keep track of/play with memes that break out on the microblogging service.

Some of these are topical: Responses to news or things that Twitterers think should be news. Like the #Amazonfail outbreak last spring over the retailer’s supposed censorship of gay-themed books. Others are the equivalent of a party game played by people all over the world. I liked #oneletteroffmovies, for instance.

And now, at the end of the decade: #10yearsgo.

This one seems to have struck a chord with Twitterers, and that makes plenty of sense. Seeing what everyone else was up to a decade ago is great voyeuristic fun, and telling everyone what you were doing a decade ago is great narcissistic fun. That’s Twitter, no?

And in case you care, I’m with Alberto Santos on this one. I was spending a lot of time playing this song:

Prince – 1999

And if you’re still reading this far into the post: Thanks for reading what I had to say this year, and thanks for letting me know what’s on your mind, too. Gotta go make a lot of lasagna. See you in 2010.

[Image credit: Beverly & Pack]

Last fall, a small but vocal group of Twitterers managed to shame Johnson & Johnson (JNJ) into apologizing for one of its Motrin ads.

This weekend’s replay: a howl of outrage, amplified and directed via Twitter at Amazon (AMZN), which may or may not have instituted a boneheaded policy  regarding “adult” books on its site. Or “adult” books aimed at gay and lesbian readers. Or something.

What happened? It’s not clear. But search for “#amazonfail” on Twitter and you’ll find that many Twitterers believe that Amazon has stripped the sales rankings from all manner of books that deal with gay and lesbian, and/or “adult” topics, making them less likely to appear on the site. In essence, the Twittersphere charges Amazon with trying to hide material it finds distasteful or that it thinks some customers will find distasteful.

Example: Amazon’s listing for Annie Proulx’s “Brokeback Mountain” doesn’t have a sales rank. But the author’s newest book does have one.

From what I can tell, the meme started up on Saturday, but didn’t start building steam until Sunday afternoon, when I noticed mild-mannered types like New Yorker writer Susan Orlean railing about Amazon on Twitter.

And it’s still going. As I type this, after 10 p.m. Eastern on Sunday night, the “amazonfail” keyword is generating a dozen hits on Twitter’s search page every couple of seconds.

Amazon hasn’t helped its case by remaining more or less mute throughout the weekend. But, by Sunday evening, the retailer had issued the same line to me and several other reporters: “We recently discovered a glitch to our Amazon sales rank feature that is in the process of being fixed. We’re working to correct the problem as quickly as possible.”

Not a terribly illuminating response, and I’ve asked for more information. But no matter what really happened, Amazon now has a real problem on its hands: A vocal group of people believe the retailer has discriminated in some way against gays and lesbians.

When Johnson & Johnson got caught in the Twitterstorm last fall, it had a relatively easy way out: A profuse apology to people it had offended. But Motrin has a very specific customer base and Amazon has a much broader one, and anything it says or does regarding gays, lesbians and “adult” material of any stripe is bound to upset some people.

But the company should do the right thing and clear the air anyway.

UPDATE: Here’s an apology from Amazon, which doesn’t really explain what happened, but says the problem didn’t just affect books aimed at gays and lesbians.