My latest Amazon.com shipment included what is shaping up to be my favourite book in the area of mathematical physics: Doran and Lasenby's "Geometric Algebra for Physicists".
The elegance of geometric algebra is clearly evident in that fact that Maxwell's equations become a single equation in this algebra. I recall my delight when I discovered that a tensor treatment of Maxwell's equations resulted in two equations instead of four. This takes that to the next level.
It got me thinking that it would be fun to put together a document that took the reader on a tour of vector calculus, tensors and geometric algebra, in each case using Maxwell's equations as the common thread.