Because everyday objects reflect infrared in proportions that differ sharply from that of visible light, the tonal relationships are wildly unexpected. Such near-infrared techniques used in photography give subjects an exotic, antique look. Green vegetation becomes white, whereas human skin becomes pale and ghostly. The resulting images look alien.
Digital cameras use CCD and other similar sensors to capture infrared images. Although all digital cameras available on the market are sensitive to infrared light, they are equipped with infrared-blocking filters. The main reason for this is that consumer cameras are designed to capture visible light. But sometimes these filters are used together, giving very interesting in-camera effects like false color, wood effects etc.
Mark Grealish

Omar Junior

NASA

Jernej Verbovsek

G2-Studio Photography

Orange Bread

Naomi Frost

Corrado Borean

Daniella T

Cavagna Ottavio

Bruna Marchioro

source: http://www.smashingmagazine.com/2009/01/11/40-incredible-near-infrared-photos/