This poll has a mix of brands and mobile operating systems. If your phone happens to fall into two categories (such as being both an Android phone and a Motorola phone), then go with the operating system which will indicate to us that you're using a smartphone.
If you happen to use more than one phone, then just pick your primary one (or your favorite one). And if your mobile device of choice isn't listed in the poll then pick "Other" and specify the device in the comments.
Easy? Any questions? Good. Go vote.