Ok the tutorial made it clear

sure, np.

Here's a tutorial...http://img155.imageshack.us/img155/4020/aate0.png

Basically, it's getting a color around edges of lines to smooth them out so they don't look so pixelly.

Here's an example in a font to make it smooth..http://www.pixeljoint.com/pixelart/50128.htm

And here's very smooth work with it as well....http://www.pixeljoint.com/pixelart/31876.htm#

Could you point me to a good example of a pixel art with anti-aliasing?

Those were special days compared to now

the lineart is pretty good, but this seriously needs some AA. Also, the colors could use more contrast.

Even if you spend about 20 minutes on this you could vastly improve it, since the lineart is a good base.

Rule number 97: Concentrate!
Rule number 98: AIM!!

Ahh, I miss the good old days, before iCarly, The Jonas Brothers, and...Hannah Mon-freakin'-tana!