GrandCentral, is a client who along with client Covad, sponsored the GigaOm LaunchPad party at O'Reilly's eTel conference. GrandCentral was the buzz of the show, captured the title in the Mozes voting and recently was written up in the highly read David Pogue NY Times column complete with video that was hilarious.
Today Tim O'Reilly in his Radar column penned a piece about GrandCentral being the Web 2.0 address book. I think it's more than that and at the same time VoIP 2.0 along the lines of the Voice 2.0 Manifesto that pal and client Alec Saunders authored and which Yahoo's Brad Garlinghouse and Jeff Bonforte have also articulated over the past 18 months of so, as did former AOL Sr. VP Ragui Kamel.
I say this because GrandCentral:
1) Simplifies my life
2) Works with both VoIP and PSTN as well as Mobile the same way (Jeff Bonforte might call this 3.0 for that very reason)
3) It doesn't care how I check my messages, from where or on what device.
4) It finds me, but can also be told not to.
5) It's friendly to partners and doesn't make anyone an enemy. Mobile, Landline and VoIP all can work with it
There's a lot more that makes GrandCentral powerful, but at this point I think Craig and Vincent are past 2.0 in vision, while still working somewhere between 1.0 and 3.0..