If you've been running Butler for a while, you won't have a few items that the new versions come with, such as a Wikipedia search engine ready to use.

You can set it up so that you can either type in your search terms or have it perform a search on the text that is currently in the Clipboard.

To type the search terms:

1. Add the search engine:

Open your Butler configuration window, click on 'Engines'.
Command-N to create a new search engine. It will default to show you the Prefix and Suffix fields on the right side.
In the Prefix field, paste this line:
http://en.wikipedia.org/wiki/Special:Search?search=

In the Suffix field, enter this:
&go=Go

Name the engine whatever you like, I went with 'Wiki'.

2. Create the Web Search interface:

Back to your main Configuration, choose 'Web Search' from the '+▼ Smart Items' menu (+>Smart Items>Web Search).
Choose the name you gave to the Wikipedia engine.
Set a keyboard command to open it with, and you should be all set.

To use copied text:

Copy and paste this AppleScript into a new Butler AppleScript item. This is useful if you have selected and copied the text you want to search. It simply takes the contents of the clipboard and searches with that.

tell application "System Events"
set cha_foo to (get the clipboard) as string
open location "http://en.wikipedia.org/wiki/Special:Search?search=" & cha_foo & "&go=Go"
end tell