• sprite-margin since version 0.2
• sprite-background since version 0.5
• sprite-colorcount since version 0.5
• sprite-dataurl since version 0.5

.imageclass1 {
	display:block;
	width: 50px;
	height: 21px;	
	background-image: url('path/image_1.png');
	 
}

.imageclass2 {
	display:block;
	width: 50px;
	height: 21px;	
	background-image: url('path/image_2.png');
	
}

/**	sprite: mysprite;
	sprite-image: url('path/mysprite.gif');
	sprite-margin: 30; 
	sprite-background: #bfcad9;
	sprite-colorcount: 65536;
	sprite-dataurl: true;
	sprite-layout: vertical; */

.imageclass1 {
	display:block;
	width: 50px;
	height: 21px;	
	background-image: url('path/image_1.png');
	/** sprite-ref: mysprite; */
}

.imageclass1 {
	display:block;
	width: 50px;
	height: 21px;	
	background-image: url('path/image_2.png'); 
	/** sprite-ref: mysprite; */ 
}

/**	sprite: mysprite;
	sprite-image: url('path/mysprite.gif');
	sprite-margin: 30; 
	sprite-layout: vertical; */

Lables the smarsprite you want to be created. You can have as many as you like.
give the filename and the URL where the SmartSprite will be stored and uses after it has been created.
sprite-layout: ... sets the layout of the SmartSprite: horizontal or vertical
sprite-margin: ... sets the margin between the image files inside the spriteimage in pixel.

Notes:
supported output formats are: gif,png and jpg
if you want to have transparency supported: dont use jpg for your SmartSprite!

.imageclass1 {
	...
	...
	background-image: url('path/image_1.png');
	/** sprite-ref: mysprite; */
}

this will be replaced by the SmartSprite that you have defined in mysprite
the background-position will be calculated automatically.

Notes:
supported input-filetypes are: gif, png, jpg, swf, bmp, xbm
make sure that the sprite-ref declaration is below or 
in the same line as the background-image declaration and inside de {}-block 

.imageclass1 {
	display:block;
	width: 50px;
	height: 21px;	
	background-image: url('path/mysprite.gif') no-repeat top left;
	background-position: 0 0;
	 
}

.imageclass2 {
	display:block;
	width: 50px;
	height: 21px;	
	background-image: url('path/mysprite.gif') no-repeat top left;
	background-position: 0 -198px;
}