PhoneSpell is a search engine which provides three services:
1) Enter a phone number and see what words and phrases it spells
2) Enter the start of a phone number and see what words start with those digits
3) Enter some letters and see the corresponding phone number
So if you’re opening a business and need a new phone number, you can type in the available exchange and see what one-word numbers you can choose from.
Or if you’re looking for a toll-free number to advertise, type in the letters and find a corresponding phone number.
There’s a similar site called DialABC.
It’s got even more features than PhoneSpell.