Line2 adds a second number to your iPhone

One iPhone, two phone numbers. That's the idea behind Line2, a new telephony app that effectively adds a second line to your handset.

Despite Apple's curious claims that iPhones aren't for business, Line2 should come as good news indeed to business users. It provides a new local number, a ported existing number, or an 800 number.

Whichever option you choose, the number comes with voicemail, call history, and an independent contacts directory. (The Line2 app provides one-tap switching between your iPhone and Toktumi phone books, a nice touch.)

Using Line2 requires signing up for Toktumi's "virtual office" phone service, which costs $14.95 per month if you sign up for an annual contract or $19.95 if you go month-to-month. Thankfully, there's a 30-day trial available.

Better still, the first 200 iPhone Atlas readers who sign up for an account and use trial code 591321851 will get three months free!

All subscribers will, however, have to pony up 99 cents for the Line2 app. Though it's hard to quibble with such a paltry sum, we can't help feeling that if you're paying for monthly service, the app should be free.

Once you've installed the app and signed up for service (which, impressively, you can do right on your iPhone), calls to your new/ported/800 number come through just like regular calls.

Well, sort of. Your iPhone rings and you see your Toktumi number as the caller ID. When you answer, the automated Toktumi bot tells you who's calling and gives you the option of accepting the call or sending it directly to voice mail.

That's a nifty feature, though it does require you to activate the iPhone's keypad to make your selection, which is a minor hassle.

As for outgoing calls, Line2 provides unlimited calling to the U.S. and Canada and low-cost international calls--all routed over the usual cellular airwaves, not Wi-Fi. Toktumi wants to make it clear that Line2 isn't intended as a "cheap calling solution," but rather an option for business professionals seeking a separate number that integrates with their phone.

Of course, you can get ostensibly the same thing from Google Voice, if and when it makes its way to the App Store. (TechCrunch has more about Line2's similarities to Google Voice, if you're interested.)

In the meantime, Line2 definitely works as advertised. If you like the idea of a second phone number for your iPhone, it's worth a look.