I don't have a work-provided cell phone, but I frequently want to use my personal phone for work. However, I use a personal number on the phone, so I am loath to give it out to people I don't know that well. Many times I have asked that my cell number only be used for a specific instance, but that request often gets ignored, and suddenly I'm getting cold called.
To solve this dilemma, I've been using Google's GrandCentral for about a year, and I like it well enough despite some obvious flaws it has when used with an iPhone. I can give my GrandCentral number out, and the service looks for me at my desk, lab bench, cell phone and (occasionally) my home number. And with the GrandDialer application that showed up in Apple's App Store a few weeks ago, I also can easily place outbound calls through GrandCentral without giving up my iPhone's caller ID info.
However, GrandCentral leaves a lot to be desired. Foremost, I can't check my GrandCentral voice mail from my iPhone, because 1) the iPhone doesn't support Flash, which GrandCentral uses for its visual voice mail functionality, and 2) the iPhone won't let me download WAV files as the alternative method of message checking. I also can't move in-progress calls between lines.
At the ShowStoppers show in San Francisco last night, I ran across Newber, a new GrandCentral clone specifically designed to work with the iPhone, (although I see no reason why support won't be added for other devices in short order). In beta right now, Newber gives the user one phone number to give out--and like GrandCentral, Newber will find you on your iPhone or any land lines you may have preprogrammed. Newber also claims that its software lets you transfer in-progress calls between your various lines, and Newber will also utilize the iPhone's locationing technology (GPS or the Wi-Fi/cell tower triangulation for first-generation iPhones), to identify your lines that are nearby.
No word on what, if any, voice mail services will be available through Newber, but the company is promising better dialing options down the road, allowing users to automatically dial every number they have on file for a contact--to find them with just a click of a button.
The downside, when compared with GrandCentral, appears to be cost. While GrandCentral remains free at this time due to Google's never-ending beta cycles, Newber looks like it will cost $5 a month/2 cents a minute--although I am unclear whether those charges are either/or or cumulative.