Killer deal for dad for Father's day from Amazon...  Add Popular Science (1-year) to your cart.

After you add PopSci, click here and add Popular Mechanics too.

It will say $10 for a year but when you add it to your cart and go to the checkout, they subtract a $10 promotion so you get both magazines for $5. (look on the right side)

Dad will think you spent much more.

UPDATE: Tank tried it and he only got a $5 promo discount so he paid $5 each. ($5 for both worked for me) So you might get $5 per but still a great deal.