Generate a random number or string in PHP.

This function creates relatively secure random passwords. It's by no means ideal, but it should work in most non-critical situations. The nice thing is the generator attempts to create passwords that people can pronounce and chooses letters that won't be mistaken for others (such as the numeral "1", an upper-case "i" and a lower-case "L"). To keep the code short much of this functionality is very rudimentary, but it's better than nothing.