Does that actually work? On my machine pow has ipfw configured so that it only forwards requests to 127.0.0.1 not to 10.0.1.whatever so project.10.0.0.5.xip.io fails.

Filed an issue: https://github.com/37signals/pow/issues/293

Edit: a) I should RTF man page for ipfw, b) nevertheless my OS X behaved strangely. I rebooted and now everything works.

Anyway, great project, have been a happy user of pow master for quite a while.