Many webmaster are not aware of how their website will look on various resolutions. Having a 17″ monitor I can see only a maximum resolution of 1024 x 768 pixels. Later I found out this online tool that can show any website in various resolutions.
Make sure to check out
ViewLike.us 
The website is simple and designed only for this operation. The supported resolutions include:
iPhone
WII Browser
800 x 600 pixels
1024 x 768 pixels
1152 x 864 pixels
1280 x 800 pixels
1400 x 900 pixels
1600 x 1200 pixels
1920 x 1200 pixels
Cons:
With this online tool, a person can only view a website on the selected resolution. The tool fails to give other features like capturing an image of the website and saving them.
The list of resolution is very limited. They must have an option for the user to enter their own custom resolution, no matter monitor display comes with fixed series of resolutions.
