Of course you could use the ‘exactly’ option to search for the image, for an image to fit your exact size requirement. However an easier and faster method would be to just add the ‘imagesize:wxh’ parameter to your search phrase, where w is the width and h is the height of the image.

Example: imagesize:300×250 brad pitt, shows you images of brad pitt, with the image dimensions as 300 width and 250 height. Certainly save me a lot of time!

Its very easy to add this search box to your site. In fact if you don’t prefer to install it directly and want to test it, just go to their site sikbox.com and enter your blog’s address. There is a live preview search box, using which you can test the results. A live preview of makeuseof.com yielded the following results:

To add the widget to your blog just go to http://sikbox.com/ and fill in the preview form. Then just click on the ‘Get the Code’ button. Now you will be asked for your name and email. Fill it up and click on the ‘Customize and Generate Code’ button. Now you can customize the search-box (actually you customize how the results appear) and then select the code generated below and add it to your blog.

Advantages:

• Free and fast
• Ease of use, no complexity
• Easy to install and use
• No programming required
• Extremely fast and lightweight
• Fully customizable via skins or CSS
• Image search support

Disadvantage:

The only disadvantage that I found was that for the search results to appear properly, your site must be indexed by Yahoo. This is because the  widget uses Yahoo API to get the results. Otherwise its a great plugin

You can try it out by visiting sikbox.com