If you are going to set up a search engine to index tech content, like, say, a tech discussion forum, its really stupid to automatically exclude two or three letter terms from the index given the ubiquity of short acronyms. If you insist on dismissing short terms as being unlikely to generate a search result, I’d suggest a somewhat more intensive approach: compare the term to a dictionary of common english terms and only index the ones that don’t match.
uh…but that would be, like, hard -n- stuff