understanding voltage, plugs, conversions

[mollymore]

Hey y'all, I'm in England! How exciting.

Coming from Canada, and I've got with me my ibook, and my canon powershot. I have a plug converter that will work with my cell phone but I've been using my friend's voltage converter to charge my laptop and camera batteries. My question is: how do I figure out if I need to use the voltage converter, or whether the plug converter will work fine? What are all these numbers, what do they mean, which are the important ones in this case, and how do I figure this out? Any information or advice?

I'm leaving the laptop here but taking the camera as I head to France and Spain. I don't want to lug a voltage converter around for my camera if the plug converter will work, since it weighs a lot less.

Thanks!

Molly