GrandCentral, which just recently got acquired by Google, is one of the most insanely useful services out there. It uses the power of VoIP to route calls where ever you happen to be, but all that magic is transparent to you, the user.

Meanwhile, TalkPlus gives you the ability to tie multiple phone numbers to your mobile phone. With their new Nokia S60 3rd Edition client

that is currently in beta, you can easily and transparently make calls as any one of their numbers. An up-and-coming feature of TalkPlus is the ability to alias any number to your mobile phone, allowing you to make a call as if you're coming from that number.

Ken Camp, meanwhile, has obtained access to this “aliasing” feature thru TalkPlus and was doing something very sensible: aliasing his GrandCentral number with TalkPlus. Apparently, there is some issue with this that the GrandCentral guys are working on.

While there is some debate about whether or not GrandCentral and TalkPlus are competitive services, I don't believe they are. They attack very different problems with similar solutions. GrandCentral, and now Google, are about one number. TalkPlus embraces the multiple-number lifestyle and gives you a tool to manage it. Having them work together would be fantastic, and I have no doubt it will happen.