hack off sh filename extension
better ruby version, no big need to segregate gems by ruby patchlevel
Add an OHMYGEMS_ROOT much like RBENV_ROOT for overriding default

I set my OHMYGEMS_ROOT=/usr/local/var/gem

This allows Pow to access the gemset.
In your project, add to .powenv:
source /usr/local/etc/ohmygems
ohmygems <your-project>