Taking your smartphone abroad? Here's what you need to know

I've had friends who thought that they could take their smartphone abroad and use it just like at home. If you have a phone that uses the GSM band (T-Mobile, AT&T) that's generally true. But with AT&T you could be paying every time your phone receives a data update (apps, for example) or if you use any of the normal functions (email, texting, GPS). And don't get me started with what phone calls can cost -- $2 a minute and more!

T-Mobile is more forgiving -- you can generally get free texting and free data (email, surfing the web, etc.). You'll pay 20 cents a minute in most cases with phone calls but this is far more reasonable than most plans. And if you have Skype or WhatsApp you can use free data to make phone calls.

But there's more to know. Here it is: phone home