The Huffington Post  |  By Betsy IsaacsonPosted: 03/21/2013 11:32 am EDT  |  Updated: 03/21/2013 3:21 pm EDT

Question: What are my options for placing a call from my Google Voice number — especially if I don’t have phone service handy?

Answer: It could not be much more straightforward to use Google’s mostly-free service to manage incoming calls: Log into your account, add a “forwarding phone,” and calls to your GV number ring there automatically.

Google, however, lists four different ways to place calls from your Google Voice number (as opposed to having whatever random number you might be using appear on the other person’s Caller ID).

You can use its smartphone apps to place calls from your account — but each does so differently. In Android, you use that app to select whether outgoing calls should automatically come from your Google Voice number or only when you request it. But in iOS, you can dial directly from the app. And in BlackBerry, you can either dial from Google’s app or select a menu item in the address book.

In all of those cases, you can send text messages right from Google’s app.

Or you can call your Google Voice number from any phone, enter your PIN, press 2, enter the number and then hit the pound key. That’s how I place free long-distance calls from home–using a decades-old Trimline corded phone.

If you’re in front of a Web browser, two last options become available.

If you’re logged into the Google Voice page, click the “CALL” button, enter the number and Google will dial your phone, then connect you to that number; the “TEXT” button sends text messages directly.

You can also place a call from within Gmail by clicking the phone-icon button in the leftmost column. But the last few times I tried that from my desktop, the person on the other end couldn’t hear anything I said and promptly hung up.

But what if you want to call from a device or an area with only data available, not voice? In that case, third-party apps can turn Google Voice into the Internet-calling service you might have once assumed it could be.

In Android, I’ve been trying the the paid version of snrb Labs’ GrooVe IP (available in a free, ad-subsidized version and in a $4.99 edition with added features). On iOS, I set up the free version of TalkMeIM’s Talkatone (a $19.99 a year fee removes the ads and activates a few extra options).

Both worked fine at placing calls, although weaker Wi-Fi made some calls awkward. GrooVe IP also had a much cleaner interface than Talkatone, even setting aside the distracting ads.

To receive calls in these apps, you need to enable call forwarding to your Google Chat address. You will want to disable that option if you happen to install either app on a phone you use for regular calling, lest you get stuck with the bizarre situation of both the regular phone app and a third-party GV tool ringing at the same time.

Tip: Airplane mode + WiFi = no international roaming surprises

If you need to take a phone overseas that happens to be compatible with networks in wherever you’re going (in most cases, one based on the GSM standard), your carrier will gladly charge you steep roaming fees for the privilege of calling and clicking outside the U.S.

You can instead add a somewhat discounted roaming option to your service plan before you go, but can still pad out your bill to a painful degree.

Getting your phone unlocked beforehand, so you can buy a prepaid Subscriber Identity Module card and pop it into the device when you arrive, will slash those costs. But that may not be a quick transaction, and your new SIM may not come online right away either–I waited about six hours after buying one in Germany last August.

But if you only need to check the Internet a few times a day (and maybe have one of those Google Voice Internet-calling apps for the occasional call), you may not need regular service at all. When you land, don’t take the phone out of airplane mode at all–but do enable WiFi. At a minimum, that will ensure no unpleasant surprises on the bill when you get home, while still allowing the occasional online fix at a coffee shop or hotel.

You wouldn’t think we’d need a new mobile operating system for smartphones, what with the current dominance of Android and iOS, and challenges from BlackBerry and Windows. The folks at Mozilla beg to differ. At Mobile World Congress, in Barcelona, Mozilla, which is best known for its Firefox Web browser on personal computers, is previewing Firefox OS, an “open mobile ecosystem” aimed at smartphones around the world.

Mozilla plans to launch the new operating system in global markets where consumers are transitioning from so-called “feature phones” (an oxymoronic name if ever there was one) to smartphones. The first wave of Firefox OS devices is expected to arrive this summer and reach consumers in Brazil, Colombia, Hungary, Mexico, Montenegro, Poland, Serbia, Spain and Venezuela. The U.S. is on the roadmap too, but availability is likely to come later.

Sprint is the only one of the 18 announced mobile operators that plan to support Firefox OS that is likely to be familiar to most American cellphone users, an operator roster that includes América Móvil, China Unicom, Deutsche Telekom, Etisalat, Hutchison Three Group, KDDI, KT, MegaFon, Qtel, SingTel, Smart, Telecom Italia Group, Telefónica, Telenor, Telstra, TMN and VimpelCom.

But Mozilla does plan to offer some familiar apps as part of a Firefox Marketplace that will simultaneously launch with the new operating system. The app list (or outfits that plan to supply apps) include AccuWeather, Airbnb, Box, Cut the Rope, Disney Mobile Games, EA Games, Facebook, MTV Brasil, Nokia HERE, SoundCloud and Twitter.

Mozilla says people will be able to use an app one time without actually having to install it. The idea is that by consuming an app on demand, you’ll be able to determine if this is the kind of content you want on your smartphone.

Even so, it is worth begging the question of whether there’s room for another OS? Mozilla Senior Vice President of Products Jay Sullivan maintains that there is and says a major advantage of Firefox OS is that developers don’t have to learn something new, given their limited time and resources. Indeed, developers can build Firefox OS apps using familiar Web technologies such as HTML5. “We expect to see lots of amazing apps people love built for Firefox OS because more developers are already creating for the Web than for any other platform,” Sullivan says.

IDC mobile analyst John Jackson says Mozilla’s efforts so far represent “a good start toward resolving the chicken and egg problem where developers will tend to hang back to wait for (traction) in the market while users wait for products that offer access to lots of third party services. It’s hard to understate the strategic significance of emerging market positions for virtually all competitors in the OS or mobile device domains.”

The challenges may be even greater the U.S. “It’s not clear to me that there will be much initial appeal in the U.S.,” says Jackson. “Having said that, I think the U.S. is an opportunistic market for Mozilla and Sprint for now, and will have to see how the offer is packaged and promoted.”