In this case, the Athens games of 2004. This stamp celebrates Greek athlete Hrysopiyi "Piyi" Devetzi's silver medal placement in the triple jump event.
N is for Nebula, in this case a ring nebula, on this stamp that was slightly damaged in transit. I have a feeling that more recent stamps are made of stronger stuff to survive the seemingly more aggressive sorting machines.
This stamp was issued in 2000 in honor of the Hubble telescope and the astronomer it is named after.
A Canadian stamp for L, The Loyalists, on this current trip through the alphabet for Sunday Stamps.
This stamp was issued in 1984, and commemorates the approximately 50,000 American colonists who remained loyal to the British crown and made their way north to settle in Ontario, Quebec and the Maritime provinces after the conclusion of the American Revolutionary War. The flag in the background is the Grand Union Flag, in use from 1606 to 1801. For links to more topics with an L theme, head over to Sunday Stamps.