D-Link has a nice feature on their website that really helps people like me when I am trying to support a client who users one of these devices.
Normally when I am supporting someone I login remotely so I can view their screen and make the changes for them right there on their computer. But if their router is down, they usually can't get internet access to allow for this to happen.
So, it can be pretty difficult to talk to someone on the phone with stuff like "Ok, do you see anywhere on the screen where it talks about setting up PPPoE information? Maybe something regarding WAN connectivity?"
But, if you get their D-Link model number, you can go to the device page on DLinks website and launch an emulator of their web interface.
For example: http://www.dlink.com/products/?pid=530
Click on "Emulator" on the right hand side.
This allows you to see the exact same screen they are looking at. It also allows you to click around to find the right page w/o asking them to click every link and read you ever bit of info.
It's a great tool, and it probably saved me an hour of time with one of my clients today.