Boolify: PubLearn's Boolean Search Tool
Visual tool for creating Boolean searches--shows search criteria as puzzle pieces. Also includes a few lesson plans
Flickr: "pc40sf06"
Student projects showing trigonometry concepts through annotated Flickr images. The pink sweater is my favorite.
FeedVis: top 50 edublogs
Cool way of visualizing changes in word clouds over time in 50 of the top edublogs, pulled from their RSS feeds and continuously updated.
Periodic Table of Visualization Methods
Lots of different ways to visualize content and create graphics. Good place to go if stuck on how to represent something visually and create relevant graphics.
Visual literacy K-8
Free resources for teachers with information on visual literacy, focusing on visual sources of information like maps, diagrams, timelines, and storyboards