Capitalize first letter of each word in a selection using Vim

You can use the following substitution:

s/\<./\u&/g

• \< matches the start of a word
• . matches the first character of a word
• \u tells Vim to uppercase the following character in the substitution string (&)
• & means substitute whatever was matched on the left-hand side
• g means substitute all matches, not only the first