Your best option is to signup with AOL. £15/mo you get unmetered access and it can be used across Europe. There are other providers, such as British Telecom Internet, Freeserve, Tiscali, etc. but they are all extremely crap and VERY slow. Most dialup ISPs in the UK are fly-by-night companies, connections are extremely poor and don't sustain. You're extremely lucky if you can stay connected to many-a British ISP for more than 60 minutes without a dropped connection. Thank GOD for NTL Telewest!
A good choice would be to signup for an ISP that offers access on a pay-per-minute basis. Depending on the telecom provider that you hook into, it can cost anything between £0.45 and £3 per hour, but you won't have a subscription cost. I like
NetDirect by Ision Internet, but as for France and Italy... I have no idea.
Also take a look at Net 4 Nowt ("nowt" being nothern slang for "nothing"

) at
http://www.net4nowt.com/