So the way to install into non-standard places has changed in Module::Build between 0.18 and 0.20, which led to some fun this morning.
First thing I didn't realise was that because it uses itself to install itself, I should have been looking in the documentation of the 0.20 that I was wanting to install, not the 0.18 that I already had installed.
The way to get it to install in /my/own/directory is to do
perl Build.PL install_path=lib=/my/own/directory
and then
./Build install
will do the right thing. I am writing this down now as I will never remember it. The exact invocation I use is
perl Build.PL install_path=lib=/home/kake/local/share/perl/5.6.1 install_path=arch=/home/kake/local/share/perl/5.6.1/auto/ install_path=libdoc=/home/kake/local/src/man install_path=bindoc=/home/kake/local/src/man install_path=script=/home/kake/local/bin/