can

Fresh PAYG sim card, it's only available from Carphone Warehouse. It's
cost £4.99 and you get £5 worth of credit. They send you an automated
text message when your credit is low, but you have to contact them to
have it unbarred for international roaming. Text messages cost only
40p back to the UK. If you choose to top up by credit or debit card
and don't do so, when you run out of credit you can still make and
receive calls the charge will just appear of your credit or debit
card. Hope this helps.

Shafik

well, i'm there at the moment and after last time, roaming with telstra,
there was no way i was going to do that again! i've got an 02 (UK company)  
PAYG ("pay as you go" = prepaid) account. it's not exactly cheap, but for
GBP1.99 per month you can opt for cheaper EU roaming rates, with their
"Euro Bolt On". those rates are:

69p/min to anywhere in europe (ordianry landline and mobile calls)
49p/min to receive calls
39p to send a text msg.

call charges within britain include:

landlines and o2 mobiles: 25p/min for 1st 3 minutes of calls that day and
then 5p/min for rest of day.

other uk mobiles 40p/min

sms 10p / international sms 20p

international calls GBP1.50/min

you can get a cheaper international rate with a GBP5 one-off payment,
which gives you 10p sms and 35p / 10p per min peak / offpeak to EU,
usa/canada, aus/nz (plus other rates for diff places)

as i said, it's not what i'd call cheap. other uk networks may be better.  
roaming works well, including being able to display your credit on your
phone (not having to deal with some pathetic voice recognition system,
like telstra's!) and o2 seem to have best uk coverage.

will