Windows 7 Tip: 
If you have the iPhone and you are looking for some great and nice Wallpaper than you have to look this new site DailyWallPaper. Dailywallpaper lets you browse and download high quality iPhone wallpapers for free.
Features:
* Browse and download iPhone Wallpapers.
* Browse wallpaper by category Nature, 3D, Movie, Abstract, Cars, Technology etc.
* Database currently has around 270 free wallpapers and more will be added.
Hello,
Check out this web application:
wallpaperbase.mobi
It has great high quality 320×480 wallpapers for your iPhone 3g and is very easy to use and navigate.
Regards,
Billy