Are you looking for an application to simulate color blindness? Do you want to know how to implement multiple baseline grids in InDesign? What is it about the Em Square that sets moveable type apart from calligraphic stroke and how is a digital world removing this difference after 500 years? These topics and so many more are on tap daily at Typophile.
Typophile is so freaking amazing I have to share it with you once more: it is a treasure trove of all things type. Check it out!