Thanks Ian... what a good idea!
I did just that, and at least I now know the 'phone number associated with my Dell/Vodafone SIM!
While I was in a good signal area, I also tried accessing a web page or two, and was pleasantly surprised at the response, especially as I wasn't even in a 3G area!
You reply also clarified something else I had been wondering about, as BT
have also kindly given me a Vodafone SIM (plus an external dongle) with a FREE 1 GB data allowance for 18 months, which is obviously better than the 60 days (or less!) I get from Dell.
In a few weeks time, hopefully I shall just be able to insert the BT
SIM into my Mini to continue with my Mobile Broadband access!
Thanks again for your reply.