Google has dropped the reverse phone number lookup feature. Glenn from the Google Blogoscoped Forums spotted this on Friday.
That means you can no longer easily type in a phone number into Google and if Google has the phone number in their database, it won't show you who it is. Honestly, often when I receive phone calls from people I need to look up, it rarely would show who it is in Google anyway. The people who don't mind me knowing who is calling show up on the caller ID anyway - those who don't want to show on the caller ID wouldn't show on Google.
In any event, the reverse phone number lookup feature seems to be gone.
In November, Google dropped the Google Phonebook operator. So I guess this is the next logical step. Google dropped it due to complaints.
Like I said, this is not a big loss to me - being that 99% of the time I use it, Google isn't able to return anything anyway.
I should add that this does work for Google Place results. Try [845-369-68698] and you'd get a Google Map in the Google search results. Clearly here, businesses want to be found:
Forum discussion at Google Blogoscoped Forums.