I've used all the following wequests with my adult intermediate ESL
students.  One thing to remember when doing webquests:  be sure all the
links work before you send your students off to do the quest.  Even check
the night before...it's terrible when students get to a dead link.
Webquest template http://www.bestteachersites.com/web_tools/web_quest/ 
Webquest: Kathy Schrock's webquest site
http://warrensburg.k12.mo.us/webquest/teacher_quest/designing.htm 
Web quest example: travel to the Grand Canyon.
http://www.iei.uiuc.edu/travelsim 
Web quest examples
http://www.call-esl.com/samplewebquests/webquestcontents_htm.htm