Creato

Simply upload your icons individually to your theme’s “images/csprite” folder.
Go to WordPress Dashboard > Tools > CSprite > Rebuild to rebuild the sprite.
CSprite will do all the hard work of combining all the images into a single graphic.
It will create all the classes for you in the enqueued stylesheet.
You can then simply use the sprite in your theme like this:
<div class="csprite csprite-creatomatic_logo"></div>
It will name the classes according to the image names, so make sure that they are unique.
Read more about this plugin at http://www.creatomatic.co.uk/csprite-automatic-image-sprite-tool-wordpress/

CSprite

The automatic image sprite generator for WordPress

manu225

Create one sprite from different images to optimize your website loading! You can create JPG, PNG and GIF sprites.

Sprite Generator

Create one sprite from different images to optimize your website loading!

CSprite vs Sprite Generator