I convinced quite a few members of my family to subscribe to Flickr, and this is the best way to use it. This site organizes your pictures and shows them to people you know (and some you don’t know). Here’s my personal page.
By now you know about bookmarks and tags, and the best thing about Flickr is that you can tag your pictures for easy search. You can control who sees your pictures (ask me to upgrade you to Friend status to see some pictures of parties I have been to).
You can get a small “widget,” a piece of software, to insert onto your home page to put up pictures from your account. But you can also use the Flickr pictures to search for images that can help you in teaching. Try an experiment: search for the word frustrated, and see what kind of pictures come up.