If you think SWYPE is fast, there is a new competitor in town. It is called Word Flow and it is from Microsoft Windows Phone 8.1. In the video, it shows that Word Flows succeeded in completing the sentences in a record time of 18.44 seconds.
Here is the video that shows World Flows breaking the Guinness World Records of 18.53 seconds.
Actually, the Windows Phone keyboard is quite decent (according to my usage) already. With Word Flow, it should make it even better.