Check all the signalling going on and see whether they still make sense with
what I now know about cond_signal and cond_wait.

Think of other way to do streaming, possibly without having to lock the
result hash, as that seems to hold up stuff severely when there are more
than X threads at the same time trying to give their results.

Investigate whether Data::Dumper could serve as an alternative for Storable.

Add still more examples.

Add support for Thread::Needs?

Find out why Thread::Pool sometimes just dies in long running processes.

Check out whether all checks for $pool->notused are correct.