quick search using quick silver? just got my first mac os computer. 

installed quick silver. (I rely heavily on launchy in windows) 

so, the cool feature i was able to achieve on windows using launchy, is that after saving "quick search" i can search any site before even opening the browser. 

i.e. 

alt+space "g (tab) mac forum" 

this will open my browser with search results for "mac forum"

this is because i saved google quick search under "g" but it will also work with any other search i.e. "a" for amazon "wp" for wikipedia etc.. 

how can i recreate this in mac os?
This is easy and commonly done in Quicksilver.

Make sure you have the newest Web Search plug-in from qsapp.com.

There are some predefined searches you can use, or you can add your own. Look around page 90 of the manual. You might also want to see this post.