Think I have it figured out for Italy/France/UK trip

[Motel75]

Originally Posted by Bossman

May be because UK sims a very cheap, and in most cases can be had for free. On most of them you can call the USA for about 5p - 7p/min.

That's exactly what I meant. If you want to call the USA, it will cost quite a bit on your Italian SIM (the 51 cents only applies to the EU), and adding 5 GBP to the free UK SIM would be a much better way of calling home. Another reason, probably unimportant in your case, is if you need to give anyone a local number. OTOH, while data is generally pretty cheap in the UK, if you've already paid for a bunch of it in Italy, you might as well use it.

One more thing, if you're planning on coming back at some point, you might want to look at some of the other threads here about the best way to keep the SIM active (ie, in Italy, buy several small top-up codes before you go and apply them once a year; in the UK, send an SMS to someone every six months).