Another idea, should be really simple to do:
Technut (AFAIK) posted that link which gives you direct Internet Tablet Talk search from Google (http://www.google.com/cse?cx=0059812...%3Awt9tjwf2kd4). Why not just add 'Search ITT through Google' as one of the search options? We know that the built-in Search function in vBulletin is fairly limited, and presumably the Google search would cover searching the ITT wiki as well (although I haven't yet verified that).

EDIT: Corrected my hazy recollection of who originally posted that link - thanks EIPI.