Options to use iPad as remote photo viewing client

As it says here, I can use an iPad as a remote photo vieing client if I buy the WD My Book Live NAS. But I have an old NAS already and I wonder if there are any generic iPad apps that give similar function, but without restriction on a specific NAS?

Thanks.

I use Remiew

I can view any photo I saved on my PC from iPad as it gives full control on folder navigation, i.e. I can browse all folders of my pc without any restrictions.

One restriction it that it shows images only, no other file types are shown.

It was a bit tricky to set it up at first, but it works fine for me and it's free.

Soon, with iOS 5, the new 'Photostream' feature will more than likely fill this need for you:

http://www.apple.com/icloud/features/photo-stream.html

Try using a free cloud storage solution such as dropbox.com or box.net. For example, you can install the Dropbox application on any of your PCs / Macs, and upload images to a folder. On your iPad, download the Dropbox app and you will see those files show up.

Those solutions serve as an online NAS and it is free to use if you only use <1-2GB of storage space. Many other apps also support them so you can transfer files from and to your iPad.