When you specify the Custom URL for One-Touch Search, you can use "%search%" to include the current selection in the URL. It turns out that there is a "%language%" replacement string as well, which may come in handy for others.
Here are some examples (which just happen to be some built-in pre-sets from the control panel app):
http://www.google.com/search?as_q=%search%&lr=lang
http://%language%.wikipedia.org/wiki/Special
earch?search=%search%&fulltext=Search
http://search.yahoo.com/search?_adv_prop=web&ei=UT
I had a heck of a time finding this documented anywhere, so I'm posting it here in hopes that it will save others time. Hope it helps!
