This is a very cool gadget and working very nicely as an extension to your existing PDA. Even PDA is fairly small in size but it is still not very pratical to carry it with you all the time. This watch will make sure you don't miss a meeting and look up an address in an heart beat. If you are a PDA user, you should already get use to charge, hotsync regularly. So, battery life is not really a big concern. If you are very basic PDA (use only calendar & address)user, this watch can even repace your PDA. Only problem with the watch is its size. It's slightly bigger than the regular watch so you probably want to try it to see how it look on your arm befor you buy.