I recently (as in *ahem* months ago kind of recently) found two new websites that are very effective for assessing. The first one is Kahoot. I'll post about the other one later.
I LOVE Kahoot! It is a super fun, competitive, response game which you can do quizzes, discussions, or surveys on. Students compete against each other and then you can download data immediately afterwards. I used to use Clickers in the classroom, but what a pain! The batteries would be dead half the time or there wouldn't be enough clickers for all the students... All the students need here is any kind of electronic device that connects to the internet (iPods, iPads, cell phones, etc).
Another great component is the Public Kahoots option. You can use any other Kahoot that another teacher has created and there are some great ones. Just search specifically what you are looking for and then check the box on the right saying that you only want to see Kahoots that are made by teachers only.
I am a definite Kahooter and have even trained some of our staff in my district on it because I love it so much. Check it out, you won't regret it!