Lettermade This ongoing project, started in 1998, is aimed at documenting, appreciating, and recontextualizing vernacular letterforms and typography. (Design dorks rejoice!)
The Retail Alphabet Game I guessed about a third of these, but I really want to know where that letter Q comes from. I'm not desperate enough to buy a clue.
Just My Type. Sharpen your eye for letterforms by matching each close-up snapshot with the letter it came from, or test your eye for color with Color Me RGB, a couple of the interesting braincandy games from Scott Kim. (Also see his gallery of Inversions; I love "Figure", and the clickable tessellating alphabet.)