RE: Point of Sale Registers
All depends on your business.... pdxyyz has all good points, but if you are running a mom and pop place, then it may not be as good of an investment. I think overall they are a good idea, but you need to justify what you are getting out of it to the cost, do you need all the features? I know for a bar they are extreamely valuable for tracking the drinks, making sure what you buy is being sold and not given away etc...
The other question you have to ask yourself is are you computer savy enough to use all the features, or at least willing to learn. A POS system can track a lot and help you run your business by letting you know a lot of info about how things sell, tracking inventory and all that, but I know dozens of business owners who invested in them and they are used for nothing more than a glorified cash register. So not only do you need to decide that in the long run it will pay for itself and even help you make more money, but you really need to make sure you are actually willing to use it.