Text entry is indispensable in productivity and collaboration applications such as email, IM, and SMS. Without a large physical keyboard, slow text entry cripples these applications on touch screen based mobile phones. ShapeWriter lets the user simply slide a finger or stylus from letter to letter on a touch screen keyboard and lift to complete an entire word. The approximate stroke gesture is recognized as the intended word. ShapeWriter on Android supports three activities: WritingPad, gTalk, and Balloon Game. All three demonstrate and take advantage of ShapeWriter’s core technology.

http://code.google.com/android/adc_gallery/app.html?id=38