The Samsung Galaxy S2 and the Galaxy Nexus were among the few handfuls of Android handsets launched last year that supported USB OTG feature. For the unknown, the USB OTG feature allows users to directly connect a pen drive, external HDD or any other USB device to their handset, via a mini-USB adapter. Handy, eh?
However, the USB OTG feature in Galaxy Nexus has a big flaw. It does not auto-mount storage drives automatically when connected. This means that even though the handset detects your USB storage, it will not mount them, thus rendering the USB OTG feature useless.
Thankfully, one of the most popular XDA developers – Chainfire – has solved this problem via his app StickMount. The app will automatically mount mass storage devices when connected to your Galaxy Nexus. The app requires root access though, and mounts the storage devices at /sdcard/usbStorage/xxx/. The app can also automatically show a pop-up when you connect a mass storage device to your Galaxy Nexus, asking if you want to mount the storage device or not.
If the app does not work for you, blame your USB OTG cable. There are different types of USB OTG cable out there, and all of them might not work properly with your phone. StickMount can be downloaded for free from the Google Play Store.
P.S. – If you found the app helpful, go and donate some beers to Chainfire!