I've popped back to the UK for the weekend to catch up with friends and family.
Over the last few months I've become very used to having an HTC Dream phone running Android in my pocket in Switzerland, with an effectively unlimited data plan. Internet access while out and about has proven to be fantastically useful -- being able to look up maps online, get restaurant recommendations, and check travel planning websites are things are now take for granted. To say nothing of being able to pass the time on a bus by keeping up to date with my RSS feeds.
I wasn't looking forward to losing this for the duration of my stay, international data roaming charges being what they are.
So I was quite pleased to discover Three's SIM-only Pay As You Go (PAYG) offer. Hand them GBP 10 and in return receive a SIM for the phone, credit for 300 SMS messages, a 150MB download allowance, and calls to other UK numbers (landline or mobile) at 20p a minute.
Once the SIM was in the phone calling 444 to activate it, waiting 10 minutes, and then calling 444 again to activate the GBP 10 credit was sufficient to allow the phone to send and receive calls. To take advantage of the 3G connectivity I had to follow these instructions to add the Three APNs to the phone. I reproduce them here, mostly so it's easy for me to find them again...
From Settings -> Wireless controls -> Mobile networks -> Access Point names, add a new APN with the following settings:
Leave the other settings empty. That should be enough for the data connection to start working, and you can keep track of how much of the credit you've used by going to http://mobile.three.co.uk/my3 from the phone.