I bought a USB dongle in Australia during the summer to be able to access
the web using my laptop whilst there. It was bought there from the
Australian arm of VirginMobile, and worked great.

I now need to be able to have a similar arrangement both here in the UK and
also in Portugal. Not looking for anything fancy - just, say, 1GB/month for
the occasional use and at a reasonable cost.

Does anybody know if my dongle will work here/in Portugal with a locally
purchased PAYG SIM card, or do I have to buy a new one (or two)?