As you all know that Google made it possible to make calls using Google voice from Gmail. Other than making it possible, they made it free calling to USA and Canada. If you think about it, this feature is definitely helpful and imagine your family calling from India for FREE! Here is the post from Lifehacker explaining different ways to take advantage of this free calling feature in Gmail. Enjoy and leave a comment.

Get Caller ID from Your Computer

Let’s say you’ve got a landline set up with Google Voice and you don’t want to pay for caller ID. Or you just spend a lot of time staring at your computer. If you’re logged into Gmail, and someone rings up your Google Voice number, you can see who’s calling on your computer without digging your phone out of your pocket.

Transfer Calls to (and from) Your Computer to Save Cellphone Minutes

Assuming you’ve already added your Gmail Chat account as a number that can be reached through Google Voice (which also assumes you’ve signed up for Google Voice), you can transfer calls from your phone to your computer to save cellphone minutes. Here’s how it works:

1) If you’re logged into your Google account, go to theGoogle Voice phone settings page. At the bottom, you should see a new option for Google Chat (like in the image). Make sure it’s checked.

2) Now, when you’re in the midst of a call on your cellphone—let’s say you were talking to someone in the car, and now you’re home—just hit the * (asterisk) on your phone’s number pad to send the call to another Google Voice phone. If your Gmail account is open, your inbox should start ringing. Pick up in Gmail and hangup your cellphone.

The opposite works, as well—i.e., transferring calls out from Gmail to your cellphone. Oh, and remember: If you’ve got a decent Bluetooth headset, you should also be able to stay relatively mobile, even if you’re talking from your computer.

Find Your Misplaced Phone

Misplace your cellphone under a pile of clothes or deep in your couch cushions? If you left your ringer on but don’t have another phone on hand, just log into Gmail, dial your cellphone number, and follow the faint sound of ringing.

Use It for a Quick-and-Dirty Speakerphone for Group Calls

Google Voice is already pretty good at setting up conference calls (demonstrated in the video above). Now that you can call from your computer, you’ve also got a quick-and-dirty speakerphone perfect for the group of people sitting around a table on your coast.

Make a Quick Followup Call in Response to an Email

This is less of an “amazing new thing” than a nice, practical side effect of having one more thing integrated with your inbox. Say you get an email from a colleague. You want to send a quick followup, but it’s going to be a lot more appropriate talking than typing a reply. Dial the person up in Gmail and talk it out without disrupting your workflow.

Secretly Record Calls

Google Voice has handy recording function, but whenever you enable it (hit 4 to start and finish recording), Google Voice announces “This call is now being recorded.” Prefer to record a conversation surreptitiously? Calling from Gmail puts the audio on your computer, where you can use any number of tools to record your system audio on-the-sly. (For example, despite what I thought at the time, Whitson later told me he wasn’t aware I was recording the call in the video above.) File this under the know-your-state-laws category.

Prank Time

Speaking of neat things you can do now that your computer hardware is accessible for both inputs and outputs, consider this: If you set your onboard system audio as your default input device rather than a microphone, you can, say, play the caller a little song. That’s maybe a little boring. On the other hand, it’s even easier to navigate to your favorite prank call soundboard and have a little fun.

Make Free Calls Anywhere You’ve Got Free Wi-Fi

Your mileage may vary on this one, but anywhere you’ve got your laptop and free Wi-Fi—like, say, any Starbucks in the U.S.—you can fire up a free phone call to anyone in the U.S. or Canada and chat away. There’s a good chance that many free Wi-Fi hotspots don’t provide you with enough bandwidth to make high enough quality calls, but if you’re desperate to save on minutes (or just don’t have a phone handy), it’s worth a try.