I found a web site that gives a good collection of wallpapers free.
I know that all of you may think thats just another web site that gives wallpapers.But what I feel there was that wall papers were categorized as,
- Wallpapers by colors:
Not only like this they have provided wallpapers for widescreen & PDA
And also you can upload the images you feel to share with others.
I hope that you also know the places which gives a good collection of wallpapers and looking for them as comments.