you can enter your search query in this form:
g whatever ---remember to put space after g
w whatever ---remember to put space after w
................
...........
(only one at a time, currently )
and use a script like this:
http://dl.getdropbox.com/u/872430/Quicksilver%20Scripts/searchesQS.scpt
That way you won't have to clutter your actions tab with many scripts.
Also, you can use one shortcut and be able to use all search sites
simply be entering the initial letter like g, w etc if you decide to use
a dialog box to enter search query instead of using Quicksilver (That
will save you from pressing keys to activate Quicksilver and entering in
text mode) like this:
http://dl.getdropbox.com/u/872430/Quicksilver%20Scripts/searchesDirect.scpt
