This is not everyday that Internet adopts a new TLD or Top Level Domain. We were quite well used to the more common .com, .net, .org, .fr and other similar national suffixes. Now, here comes .mobi targetting use by the mobile operators (mostly in telephony) a little like we had received .tv some time ago.
You are now welcome to buy your own domain name in this space. But I guess that if you only have a mobile phone in your pocket, there is no need for running.