Any easy way to do this? I don't want to mess with router port forwarding
If you are using an iOS device and your server is on the same network, you can use Bonjour/ZeroConf to quickly access it. For OS X, you can set the hostname in System Preferences > Sharing. Then just access hostname.local from the iOS device.
SHIM looks pretty promising, and runs on nodeJS https://github.com/marstall/shim
Any non-nodeJS alternatives?
On the same network? Assuming you're running a server can't you just got to your local IP:port? (or bazookaBen.local:port on a Mac)
also found Drive-In, which runs on Apache+PHP https://github.com/scottjehl/Drive-In
If you're on the same lan it's as simple as going to the IP address of the local server on your phone.
I recently tried exactly this. Running MAMP on my MacBook pro, went to 192.168.0.5 (my MacBook's IP address) on my iPhone while connected to the same wifi as the MacBook and there was the MAMP localhost page.
The only problem is (as far as I know) there's no way to edit /etc/hosts on an iPhone (although I imagine you can do it on Android), so it has to be IP based.