How add add ReTweet, Buzz, Like, etc, buttons to my blog

I need help adding these buttons to my blog: I would like it so it shows the buttons on every post without me having to add them every time manually. I would like them to appear somewhat like on this blog: http://techcrunch.com/ but it does not have to look that good.

If it is possible to add the facebook like button, and the twitter retweet button, etc, please let me know how to do it.

 

maybe get a theme that has them built in ?

 

for example AddThis
http://addthis.com/
offers such buttons in a variety of styles
grab the one you love and add the code into your template
that's how I solved that problem on my site, in static pages as well as my blog and other dynamic pages, forums, etc