Using OTG cable to access external storage and 3G dongle on Nexus 7

**In my last posts, I wrote **about how to root your Nexus 7 and install Ubuntu Touch. Today I am going to write about how to use an OTG cable to access pen drives and External Hard drives. Also one of the most awesome thing you can do is to use 3G dongle on the Nexus 7. And I am doing it in questionnaire style.
Why use OTG cable?
You can use an OTG cable to attach following devices to your Nexus 7:

1. Pen drives
2. Memory card readers
3. External Hard Drives
4. 3G Dongle
5. USB Mouse and Keyboard
   What is an OTG cable looks like?
   Shown clockwise from top left: OTG Cable, Card Reader, Pen Drive, an Huawei 3G dongle (with Airtel connection).
   Yup, OTG cable is that small. Some other variants of OTG cable also comes with no wire. Refer this.
   
   Can any OTG cable be used with Nexus 7?
   **

**I had some worries about this. So I thought to buy

this OTG cable from flipkart. Some reviews says it works while others stated it doesn’t. So I went to a local market. Bought the cheapest OTG cable in just Rs 50. And it worked flawlessly.
Requirement of using an OTG cable:
Nexus 7 should be rooted and SU installed. If you don’t want to root your device, there is an alternative available. Goto Alternative.
So, after rooting, just install the following app: StickMount
There, now you are ready to use the features bestowed by a rooted device and an OTG cable. Yes, it was that simple.
Just attach the OTG cable with Nexus 7, and attach a pen drive or external storage to the other end. You should see a pop up about granting SU access to StickMount. Just grant it access, and the external storage should mount, on the location: /SDCard/usbstorage. You can open this folder to view all the files on your external storage, and use them just like it were on your tab.
Using 3G Dongle with Nexus 7:
To use a dongle with the tab requirements are:

1. Rooted with SU app installed
2. This app: PPP Widget
3. A compatible 3G dongle.
   As per this post on XDA forum, following devices are confirmed as compatible to N7:

 
But if you already have a 3G dongle then just test if it works on a desktop Linux OS. And if it works then it should work with N7 too.
I was able to get my hands on a dongle model: Huawei E1731. It took a week to activate the 3G sim to start (due to my laziness).
When you have the OTG cable and a working 3G dongle, just attach the dongle to N7 using the cable. PPP Widget should detect it and show you the option to “connect it”. But before connecting I had to set APN. So I went to Settings (from the widget itself). And set airtelgprs.com as the APN. Your APN vary and you may need to ask the correct APN from customer care. Thats it. I didn’t have to set any other thing.
After that I just tapped, “Connect”, and voila I could surf Internet through the dongle. Click Spoiler to see some states of PPP Widget:

 
And oh btw, about the last use of OTG cable. I tested a desktop USB mouse and a desktop USB keyboard with the tab. Both worked flawlessly. Using mouse I could click any app using a mouse cursor that pops up. And through keyboard, I could use Alt + Tab to navigate recent application list, Escape to go back and close any app and of course type to type anywhere where a Text field is there. It’s Amazing!
Alternative of rooting and still be able to use a Pen drive:
You can use this paid app (Rs 216): Nexus Media Importer to browse multimedia content from your Pen drive. But it doesn’t give the freedom of using the external drive like it does by accessing it “directly” from a file manager. Plus you may not use a 3G dongle without rooting. As per this page you *can* use mouse and keyboard without rooting. However it doesn’t mention an OTG cable. So I can’t be sure.
Only thing now remain is to buy a USB hub, and I could then use multiple devices, cause you know, there is just one MicroUSB on the device.  I would soon update the post to let my readers know if that’s possible.