You probably know that if you want to limit your google search just to a given site, you can do that by specifying site: parameter.
So, to search stanford philosophy encyclopedia for entries of Husserl, you would write the following in the google search box:
site:plato.stanford.edu husserl
Firefox only
Of course, it is tiresome to write that first part all the times, so you can add predefined keyword searches to your browser. Go to the Bookmarks menu, then open the Quick Searches submenu. Right click there, and choose Add New Bookmark… option. Write whatever you want in name and description fields (e.g. google SEP), type st in the keyword field, and put in the location field:
http:/www.google.com/search?q=site:plato.stanford.edu+%s
After this you can click on the address bar (or click ctrl+l or alt+d to go there) and write:
st husserl
You can add multiple keyword searches, (by default you already have wp for wikipedia).
End Firefox only
If you want to search several philosophy sites at once, there is also a solution. You can define multiple sites searches in Rollyo, and then reuse them. I defined an example with few philosophy sites. Click the picture to go there.
Rollyo uses Yahoo search engine in the background.
Firefox only
Rollyo also has option so you can add the specified search in the search bar, so you don’t have to go to the site in order to do the search.
Or… you can define a keyword shortcut for the search, using the unique id every searchroll (that is the name for defined group search on Rollyo) has. For example, for philosearch , I will set keyword field to ph and following in the location field when adding bookmark with keyword:
http://rollyo.com/search.html?sid=66633&q=%s
Now I can search multiple sites for Husserl just by going to the address bar and typing:
ph husserl
End Firefox only
Of course you can download firefox browser for free.
A brood comb 
Great tips.
Also, the function key “F6” is a quick way to switch the focus to the browser’s address bar.
Didn’t know that, thanks. :)