Venn diagram (capitalize name, after John Venn [1834–1923], British logician)
vice president (see capitalization rules for President / president)
vice versa
videocassette (closed, according to WNWD)
videotape (n. and v.)
videotaped
viewpoint
Visa (the ® should be omitted)
visual-motor skills
visual priming task
voicemail
Voices in Urban Education (Note that this journal does not use issue numbers)
Voices from the Middle (Note lowercase f; this follows style of official title)
VoiceThread
vs. (Note the period)
Because versus is a preposition, when vs. appears in a title it should be set in lowercase.