Make sure you stock up on forever stamps before the Month of Letters Challenge begins. In the U.S. rates go up on the 27th of January, so get thee to the post office by the 26th.

Highlights of the new single-piece First-Class Mail pricing, effective Jan. 27, 2013 include:

• Letters (1oz.) — 1-cent increase to 46 cents
• Letters additional ounces — unchanged at 20 cents
• Letters to all international destinations (1oz.) — $1.10
• Postcards — 1-cent increase to 33 cents