Biggest need in the VoIP space: Web-based, carrier-neutral universal VoIP phone directory

Wouldn't it be great if there was a Web-based centralized directory of inbound VoIP phone numbers from all carriers?

A third-party website where customers of Vonage, Skype's SkypeIn service, Packet8, AT&T CallVantage, Verizon VoiceWing, and pretty much any other IP phone service you could think of could list their inbound numbers?

Something that would take the cludginess out of letting everyone know what your new, say, Vonage or SkypeIn phone number is?

This service has been tried in baby steps, but there's so much more to go. And such an upside, that I cannot believe this wouldn't be a huge hit.

Yes, I know about privacy, but youcould opt out and get an unlisted number just like you have been able to do with Ma Bell since the earliest days.

Since VoIP pretty much eliminates locality-based considerations, you could have one VoIP directory assistance site for all of North America. Heck, the world.

I envision the listings as a five-column user interface consisting of last name, first name, email address (instead of physical addy as the dead-tree phone directories offer), phone number, and service provider.

Additionally the phone number would be hyperlinked so that when that number is clicked on, your default softphone would automatically dial the number. 

The service could be advertising-supported (VoIP calling services, equipment makers, or other tech-friendly advertisers).  Such a service could charge access based on an all-you-can eat, subscription based model. 

There's a big, honkin', crying, loud need for a universal VoIP phone number directory.

Would you use one?

And if any VCs are out there, is this something you would fund?