The iPhone now boasts GPS applications -- but can you trust them to get you where you're going?

When it comes to driving directions, Stacy Nisenson cannot imagine getting around without a GPS.

"We were getting lost and I found MapQuest was a pain to use. You have to get on the computer, you have to log in. It's easier just to have it ready and accessible," Stacy said.

Besides her portable GPS, her Blackberry also has GPS navigation.

"I don't use the phone. I don't find it easy to use." she said.

Now, iPhone users can get navigation applications for their phones. They include the $100 Tomtom application, the $10 a month AT&T Navigator, and the Gmap Regional Maps by Xroad, starting at $35.

Consumer Reports found these applications convenient and easy to use. But none of the ones tested worked as well as a good portable GPS.

"The accuracy is not as precise, the sound not as crisp and the volume not as high," Jeff Bartlett of Consumer Reports said.

And some of the applications don't name the street where you need to turn, a very helpful feature that's common with portable GPS devices.

For example, directions from the iPhone application only said, "in point two miles, turn right."

Plus, your directions are interrupted if you make or take a call. If you need more than occasional directions, Consumer Reports recommends getting a portable GPS. The Garmin Nuvi is a Consumer Reports Best Buy at around $250. It comes with free traffic reports as well as Bluetooth connectivity.

There's another disadvantage to using iPhone navigation application. The phones don't come with a charger or a mount for your car so you have to pay extra for those, which is around $50.

With a report from CTV British Columbia's Chris Olsen.