Postage stamps have evolved quite a bit since Great Britain's 1840 Penny Black, the world's first adhesive postage stamp. From simple designs featuring the monarch to works of art literally condensed to postage stamp size, hundreds of thousands of different stamps have been issued in the past 164 years--and the great majority of them remain reasonably priced for collectors. With so many stamps to collect from so many countries, a philatelist's choices...