It's an interesting time now. It used to frustrate me how I couldn't find an address with just the phone number - despite having a white pages that contained the info. I know this was buy design, for privacy. Now if you search for a number, your bound to get a hit for it, and can work out who it belongs to. I'm sure this will fail me one day, but it hasn't yet.
Today reverse look-up is by design, it seems. The limitation before was probably printing paper and not just a design decision, I'd guess. I'm not sure whether I like the new situation, but then none of my friends actually has a landline.
