As a Developer my self I'm always looking for tool that can help my life easier and I thought that it would be good if I don't have to install it and deal with so many complexity so an online tool would be the ideal one. I found a bunch of them and and is extremely very easy to use.
1. Sprite Cow
Personaly I really love this tool. Simple and very easy to use. You just need to upload your design and select the are that you wanted for your CSS sprite. One thing to NOTE though is if you have bunch of buttons for example or actually any objects on your design, make sure that they have enough space in between. Because if not, their program won't be able to get the exact area you are specifying.
http://www.spritecow.com/
