I think there are quite a lot of them:
http://search.cpan.org/search?query=Apache::test&mode=all
that list is actually a bit decieving - I took a look at the Apache:: modules that show up and, of the few I chose at random, none used Apache::test. the only ones I know of are Ken Williams modules, namely Apache::SSI, Apache::Compress, and Apache::Filter, though there may be a few others.
--Geoff
