I have a iPhone with a Canadian provider as well (Telus). In the account management settings on their website, I've turned off international data roaming. There is absolutely no possibility of incurring charges this way.

When travelling, I have purchased prepaid mifi mobile hotspots, kinda looks like a mobile but only one button. In Australia for example, they are about $100 for the device and it comes with 8gb of data. This is far less expensive then a day of international data roaming at $10 per mb. Connect ups to 8 devices so the laptop, kindle, iPhone and iPad are all connected.

when I travel overseas with my iPhone 4 I usually just turn off the 3G, Cellular Data and the Data Roaming and the only way I'm able to get emails, use certain apps etc is by connecting to wifi. I don't take out my sim card because I still need to be able to receive calls and smses from home.

no phone needed
 

facetime doesn't need a phone number at all, otherwise it wouldn't work on the ipod touch and ipad as it does.

Just make sure you have a second email address listed in the facetime settings, and you can be reached that way just fine. you'll have to be on wifi though, unless you jailbreak.

I got around to toying with the iOS 5 on the Touch and iPhone 4. For video and text communications on Skype, iOS 5 seemed to work just about as well as it did with iOS4 on those devices.

Those whom I know to have both the Touch and iPhone 4 carry both to use Skype when traveling internationally; and it is apparently being done for battery reasons when finding a plug or lugging a charger around may be more hassle than just carrying a second device in a purse or jacket pockets.

I carry an case/battery combo from Mophie (though others make a similar case) which has an external battery which doubles my battery life. I don't carry it around town, but do use it on my international trips.

If one doesn't turn on the cell phone, an iphone lasts a long time nearly as long as an ipod touch.

I've had facetime disappear from my iPhone when I've taken my SIM card out or replaced it with a foreign one while traveling. I've had to go into the "Phone" settings and turn "FaceTime" back on in those cases.

I've also had no problems just setting "Data Roaming" to "Off" while away.

[QUOTE=GUWonder;17345071]Skype video calls work on the iTouch and pretty well at that. [I am not speaking to camera image-related or processor speed-related distinctions, but it works well enough for me in comparison to the iPhone 4.]

I've used Skype and FaceTime from China to the US and vice versa. I've found Skype a bit more troublesome with drops and video quality.

Just my take.