Vodaphone Spain pay as you go account transfered to UK, and rest of Europe? Possible?

[Przemolog]

Originally Posted by saren

I also have an emergency international phone card (to use with payphones, and a toll-free number).

Are you going to visit Poland?
So, does this card have a tool-free access number in Poland? If so, please tell me what exactly the number is - there may be some issues when calling it from payphones...

As to using SIMs from one EU country in another in order to use remaining credit - of course, it's more expensive than using local SIMs. However, the "eurotariff" sets an upper limit for costs of EU calls to at most 49 eurocents outgoing/24 incoming + national VAT(15-25%, depending on the country). So, I think than it's better (=less troublemaking) to you to use the remaning $20 on Vodafone Spain in another EU country than to look for a person willing to buy the SIM.
BTW, terms and conditions for roaming of some EU operators may extend the coverage of the "eurotariff" to some non-EU countries like Switzerland, Norway, Iceland etc.