So, what is Virtual Number? Well, it's a lot of things, and that's the beauty of Web 2.0-based voice services. I should probably call it a telecom service, since a lot of Phone.com's look and feel is very much about this. However, that's not enough to compete these days, and the real value comes from all things Phone.com offers that you can't do with a telephone service.
As the name implies, Virtual Number is a variation on Google Voice, which is a great way to go since Google has laid the groundwork for creating mass market buzz. Now the challenge is getting attention for Phone.com, and once you see what's on offer, you'll understand why it's so much more than Google Voice. To start, yes you get the Grand Central-style virtual number service and all the convenience of having all calls come to one place.
Aside from the price being right for today's economy - under $5 a month - Virtual Number has lots of other cool features that take this well beyond everyday call forwarding. Things like being able to upload your address book to enable click to call, LNP, no contract, text-based voicemail, fax, etc. Actually, I think you'll be quite surprised at how many interesting features they have - see for yourself.
Aside from this, they have some very interesting twists to encourage viral marketing, which is really the best way to grow without going broke. Two in particular would be their Reward$ Program - where you earn credits the more you use the service, along with a referral system that brings down the cost of your Virtual Number service the more new customers you bring in.
In true Web 2.0 fashion, Virtual Number will not stand still, and new features such as SMS are coming. I don't see Phone.com taking down Google any time soon, but to me they increasingly look like the prototype for a successful Web 2.0 service provider. Kudos to Ari Rabban and his team - I think they have a pretty good read what people are looking for, and aren't afraid to try new things. If you follow where telecom is going, they should be on your watch list, and if you won't take my word for it, then Garrett Smith and Fierce VoIP can vouch for me.