Telecom Italia Mobile (TIM) offers an after hours service that allows practically unlimited internet access between the hours of 5 pm and 9 am on week days and all day and night on week ends and holidays.
TIM Web Time Recharge costs €25 for a month and is actually limited to 9GB which would be difficult to exceed for normal email and browsing at GPRS speeds.
To use this, you need a GSM phone capable of GPRS or UMTS with a USB connection. I used a Motorola V220 which is a triband and works in Europe and USA.
You need to be sure that the phone is not 'locked' to a particular provider. Some phones are sponsored by the phone service provider and will only work with a SIM card from that provider. My Motorola works with any SIM card in any country.
You also need to get Motorola Mobile Phone tools software which is available on CD from Amazon for USD$ 0.85 cents plus shipping $5.00. Shop around, prices vary considerably, and make sure it will be compatible with your phone.
When setting up the software, the APN should be set to "ibox.tim.it"
You simply buy a TIM prepaid SIM card which you will use for voice calls as well, and then ask them to add Maxi Web Time Recharge.
You can also get a PCMCIA card that will hold a SIM card, but then you can only use it for internet and not for regular cellphone mobile voice calls.
Be sure to disconnect from the internet before 0900 in the morning or it could eat up your prepaid minutes.
Go to www.prepaidgsm.net/en/italia/tim.html
Vodafone has a similar service for €30 that runs 24 hours, but I think the data usage is more limited.Howard [ Just Imagine ] 04-Jul-2009