Still waiting for my account to go active, but already some reasons I'm trying out the service:
1. Even once data charges introduced, will not have to pay 50p to do a simple mail check and perhaps not even have a mail while out and about.
2. Can apparently solve the voicemail as email attachment problem using something like Hullomail until giffgaff possibly introduces it itself, as already suggested elsewhere.
3. Apparently not blocking Fring (all of the above unlike Vodafone PAYG nowadays).
4. Much better rates for calls, texts, data, bundles/goodybags.
What we Vodafone PAYG vodafone.net users still have until they shut the service down on the 10th (if I remember correctly), apart from voicemails as email attachments, is a Fax to voicemail service, that forwards the fax as an email attachment. Admittedly, this is no longer needed very often, but having to shell out a monthly fee for yet another online service number or an actual landline for these is not really worthwhile. Perhaps there are other users out there who might need this service occasionally and are willing to pay a reasonable charge per fax page received and forwarded as an email attachment. I think once vodafone.net shuts down, you could possibly corner this market, since I don't think any other mobile phone service will then offer this service anymore. Could possibly even be outsourced and connected depending on costs. Quite a few people are lamenting the loss of this service on the Vodafone help forum pages at the moment.
Just a thought and would put the cherry on the top and give me back all the services I have lost and more! :-)