Explore download and upload files to your android external storage (sd card) without plugging your device to your pc.
Just turn on your WiFi and start the server enter the provided address in your browser allow the access and you're done.
No more USB cable.
It's working over 3g data too but be careful because you might go over your data plan allowance.

You must allow the access to the network if you have installed any kind of firewall(droidwall or similar)
Do not use port 1234 it is picking up strange data and the file gets corrupted on upload.
best results are on the default 8080.