1-800-NO-SOFTWARE in salesforce website shows the No software strategy but is it a number or something like that? :)
On US phones at least the number keys have 3 (or 4) letters on each number, so dialing "1-800-NO-SOFTWARE" actually means dialing 1-800-66-76389273.
Note that that number is too long, but dialing the extra 273 at the end has no effect on most systems and will connect you to 1-800-667-6389, their real number.
It's just a catchy shorthand that's easier to remember than the number.