This website is an easy way to create flash cards. Students can upload their cards so other students can use them. It would be a good activity to start a new lesson with you could get the students each to define a few words and upload it to the class file that way it would be available for all.
Create posters with information that can be neatly presented to the class after being printed off. Instead of worrying about whether or not the glue is going to hold the pictures on you can easily create a custom poster online now.
A website that you can create quizzes on and have your students take them on the same site. You can keep a grade book in the site with their quiz scores.
Interactive website that you can type in any tag and it will come up with thousands of pictures from the location of your choice. If you type in Texas a lot of planets with cities in Texas will show up and then you can click on a city to see pictures from that specific spot.