A couple of weeks ago, some of the developers over at XDA forums managed to get USB OTG/Host Mode working on the Samsung Galaxy S running Ice Cream Sandwich. Considering how similar the Galaxy S and the Nexus S are, it was just a matter of time before the USB Host Mode/OTG was ported to the latter.
Now, sztupy – a recognized XDA developer – has released a kernel for the Nexus S, which brings USB Host Mode/OTG to the handset. The kernel is only meant for Ice Cream Sandwich based ROMs right now, but it is possible to port this feature to older Gingerbread based kernels as well.
Since the mod is still in its infancy stage, there are some issues with it. The biggest problem with the mod right now is that it requires you to provide external power to your USB devices, via either an USB Hub or a Y-Cable, which rather makes the whole process cumbersome. The developer states that only USB 2.0 based devices work and USB 1.1 (keyboard/mouse) and USB 3.0 are a strict no-no. Some users have managed to get USB keyboards and gamepads to work flawlessly on their Nexus S, so there is no harm in trying.
To try out this mod on their phone, Nexus S owners need to make sure they have root access and need to flash a custom kernel on their phone as well. They can flash either this kernel from sztupy, or the Matr1x kernel which has some other features as well.