There is a new product on the market now called Bevchek
www.bevchek.com
It is available here in Canada through BBS systems.
It's not the cheapest thing in the world but it is immediate inventory, useage, waste & sales data. It looks perfect! You can access it from any computer over the net and it gives you as much control as you want (more $$$ more control).
We have a relatively low waste and/or theft issue at our pub so it doesn't seem to warrant the cost, but in the future we may look into it more.
Kyle