This page is going to express how to connect your mobile device.
For more info see the iPod page.
Samsung Galaxy SII
Here are the steps to mount a Samsung Galaxy SII from command line:
From the smart phone: Go to settings > Wireless and network > USB utilities.
Click on the "Connect storage to PC" icon.
Now, Plug the cable into the phone and to the computer.
You will get a new screen that says "USB Connected". Click the "Connect USB storage" icon.
You will get a new colored andoid screen showing that the USB mass storage is active.
Then the device could be mounted as USB storage devices.
Reverse out your steps when you unmount.
If you have some troubles, install go-mtpfs.. For more detail, check