Visualizing The Bible gives a visual overview of more than 63,000 textual cross-references within the Bible. It’s intention is to be more beautiful than functional.
• Is primarily focussed on Islam and religion however it has a wealth of general history links and lesson plans for history teachers. The lesson plans seem quite up-to-date in their pedagogic strategies and should be useful to the teacher who's looking for a 'planning-lite' solution to their lesson delivery needs. (I promised one of the people who designed the site that I'd give it a plug. It really is good.)