Question About United Mobile And Cbw

[fuzzypuppy]

My family and I are headed to Europe for Christmas and because we all have different itineraries I thought it would be a good idea to get a cell phone to coordinate stuff.

I've already purchased a compatible phone from a friend of a friend so I'm set there. (He bought it France and used it there, then in Hong Kong and Canada, so it works)

What I need now is a bit of advice on which international SIM card to get. My research has narrowed it down to United Mobile and Geodesa. UM having a cheaper card but higher rates and Geodesa having an expesive card but lower rates. Anyone have other companies that they prefer? Why?

Also, after learning about Callback World, I'm leaning more towards UM with CBW. I have a few questions though:

So I phone the call-back number, wait for a call back then dial the desired number. The question is, which call-back number? I notice they have them in several countries but the one in Italy (one of my destinations) doesn't accept calls from mobiles. Are those local numbers more for landline customers? and would it be easier and maybe just as cost effective to use the US call back number?

Also, what if I make a mistake dialing the number...I'm a tad dyslexic and mix up numbers all the time, do I have to hang up and call again?

And it it just limited to UM that I need to wait for two call back cals using CBW?

THanks!