How to detach a mesh into two?

[lguan]

I want to color up a mesh by two different colors, how can I do ?
Thank you!

[testscreenings]

The search:
http://wiki.blender.org/index.php/Special:Search?search=materials&go=Go
Tutorial from that search:
http://wiki.blender.org/index.php/Tutorials/Multiple_Materials

PS: search is your friend!