In our efforts to continually create a more streamlined registration process, regardless of what device you are using, we've just ensured that all text-specific fields use the numeric keyboard when you're on a mobile device.
Me, personally, I love the numeric keyboard on my phone. But that's for an entirely different blog post.
Suffice to say, when somebody is filling in their phone number, credit card info or any other numeric/interger field on the race registration form on a mobile phone, it will be much easier now.