Vesper is Latin, meaning "evening star," and shares part of its meaning with the religious term evening vespers, meaning "evening prayers." The name's been around a long, long time, but started picking up more interest in 2006 because of Casino Royale, and the Bond girl called Vesper Lynd. Vesper Vivianne Ruck is the daughter of Alan Ruck and Mirielle Enos, there was a character in a Lloyd Alexander adventure series named Vesper, and she also featured in the Batman comic series as a TV and radio newscaster named Vesper Fairchild (pictured above), who had a romantic relationship with Bruce Wayne.
There are about 160 people named Vesper in the U.S. according to White Pages, 33 of which were born in 2011, and 24 in 2010. To be more accurate, Vesper is the unisex and Vespera the feminine, and the religious term came after. (See here.) Vespertine is a lesser known variant meaning "of the evening." Vespertine is more French-chic, similar in looks to Valentine, and further removed from the common "Vespa" comments. Hespera also shares the same meaning.