@Deuxdad.
You sure can! You have two possibilities to do that. In both cases you need to download and install the Pogoplug software (free or premium) on the computer that should be able to access your 'P:' drive.
1. If you want to access everything on the HD which is attached to your Pogoplug you need to enter the e-mail address and password which is registered with your Pogoplug

or

2. If you only want to access or give access to certain files and folders on that different computer, share those files and folders by entering a different e-mail address. Let's say your e-mail is 'pogoplugowner@pogoplug.com', entering this and the correct password will give you access to everything you have loaded on attached HD. If you only want to share let's say a folder on your HD containing photos with your kids, then you can share this folder using an e-mail address of your kids e.g. 'kids@pogoplug.com'. Then you have to enter within the Pogoplug software wizard that e-mail address and password. The shared file(s) will then appear in Windows Explorer as 'Files shared with me(P:).

In both cases you will not have to have your main desktop computer running because your Pogoplug is not attached to your PC but to your router. I am using a Netgear router as well and this works very well. The same applies by the way if the other computer is e.g. in your office or at your parents' house or in a friends house anywhere on the globe.
Try it - It's fantastic!

Deuxdad, yes you enabled your sister to access a folder through your PP. On the my.pogoplug.com website when you create such a share you can check a box which says that people will be asked to create a password for their share. In your case your sister gets an e-mail with a link. She clicks on this link and is taken to my.pogoplug.com and is asked to enter a password of her choice.
So she has an e-mail address and a password. This is the info she needs to access the folder you share with her on my.pogoplug.com.
Now, let's say your sister downloads the PP software and installs it on HER computer. After the installation the Pogoplug wizard starts and the first screen has two possibilities: "I am new to Pogoplug" and "I already have an account". In fact your sister has already an account. So she just needs to enter within the PP wizard her e-mail and the password she chose and this will create on HER computer the P: drive (files shared with me). This works on any computer wherever it is as long as you share something with some user.
Hope this makes sense.

Hi
My best guess is that this is possible, but sorry, I am not a IT specialist. Why is this important to you? I think if you use the PP software on all computers which access your WIFI network you should be fine. But probably you have different ideas...Good luck anyways!

Deuxdad
Sorry but this goes beyond my IT knowledge. I suggest that you sent an e-mail to the PP support team. I am sure they will be able to help you. good luck