Android: Alternative keyboards are one of Android's best features. Typist is an Android app that tests your typing speed, so you can find out which keyboard best suits your typing style.
There are 10 tests in all and duration times of one, two and three minutes. You can also let Typist randomly choose a test for you. When you finish a test, it will display your typing speed on the screen. You can then save your score to a Top 5 list and write down which keyboard you used. It doesn't fully support landscape mode yet, but hopefully the developer will add that in the future.