I'm wondering why do they come out with so many different social network?
Does it make a difference?

Here's some how to:
Go to Tweetmeme's website at: http://tweetmeme.com/. The center of the home page lists what was retweeted the most in the last 5 minutes on twitter. By taking note of what is most recently retweeted, you can keep up on the most recent trends. You can also switch to the most popular retweets in the last 24 hours and watch all incoming retweets.
2
You can also change your view of the retweets to top retweets in the last 24 hours. You can access this information by clicking the link "Top in 24 hours". The link is a bit hard to see as it is in small print and in the middle of the page.
3
Scroll down the home page and find a link to the Tweetmeme button. The Tweetmeme button helps bloggers encourage readers to retweet their content. Just cut and paste the appropriate html. When the button is clicked it will automatically retweet your article title looking something like: RT @tweetmeme Your Article Title http://tinyurl.
4
Notice the small all, news, images, video buttons near the top? If you switch to news, you will see what news received the most retweets in the last 5 minutes or 24 hours. If you switch to images, you will see what images received the most retweets and so on.
5
So why would you want to know the most popular links in the last 5 minutes? Though twitter allows you to search its entire interface using keywords, it's impossible to tell what has received the most retweets. This information helps you find some of the most popular twitter accounts and it also keeps you up-to-date with the latest buzz. So have fun with Tweetmeme!

TI DTM Mod