Using VoIP is an easy way to save money on phone calls - you can get untimed calls to fixed lines for as little as 10 to 20c, sometimes with no monthly fee.
You can buy a special IP phone to do it - this plugs into your router instead of a wall socket. But if there's a Wi-Fi network in your office, you may not need to buy any extra hardware.
What many people mightn't realise is that they can use their mobile phone as a wireless VoIP handset. VoIP software has been on Android phones for some time, although it seems that some carriers have had it removed from the phones they sell - yes, they want you to pay them when you make phone calls.
For example some of the Samsung Galaxy S III handsets (we haven't tried the new 4G Galaxy S III announced yesterday) sold in Australia include the VoIP software. (If you own a smartphone that has this feature, why not mention the make and model by adding a comment below for the benefit of your fellow BIT readers?)
To set it up, open the Phone app, press the menu button, select 'Call settings' then 'Accounts' from the 'Internet call settings' section. Click the 'Add account' button, and enter the user name, password and server as specified by your VoIP provider. With some services you may need to enter additional details in the 'Optional settings' section - be guided by the provider.
Once that's done and the connection is made, whenever you have a Wi-Fi connection and you place an outgoing call, you'll get the choice of 'Mobile phone call' or 'Internet call'. Select the latter, and enjoy your VoIP provider's low rates.
If your phone lacks the VoIP client or it isn't Android based, a search of the relevant app store should reveal a selection of apps that will do the job - just beware that some may be tied to particular services.
Get a good call rate
Technically, it's all a lot more straightforward than it may sound. The tricky part is finding a provider that offers a tariff that suits your calling pattern, and then getting the right VoIP/mobile mix. After all, staying on an existing mobile plan (for example, $80 per month) and spending $5 on VoIP calls means you're going backwards and sacrificing a little convenience. But if you can drop back to a $30 plan because you make most of your calls from the office or at home, then you're ahead - especially as VoIP calls should be cheaper than those from fixed lines.
And using your mobile this way means you don't need to invest in a special IP handset or an ATA (analog telephone adaptor - a device that lets you use a conventional phone with a VoIP service; this functionality is built into some routers).
So there's plenty to gain (especially if you make frequent or long overseas calls - at least one VoIP provider offers untimed calls to certain countries for 20c or so), and very little to lose. Even if it turns out to be a complete failure, all you've sacrificed is a few minutes of your time, perhaps $5 of credit with a VoIP provider, and maybe a few dollars for a VoIP app for your phone.