This summer I will go on a roadtrip from West to East Europe and back. Being able to call and especially access the internet are usefull items on the road so it made me wonder whether I could buy a European sim card or something that would let me access the web or make calls regardless of the country I was in.

I know of the provider Mobile Vikings that offers a European roaming package for data. Do you know of other alternatives? Data is the main priority because calling or texting within Europe isnt that expensive to begin with, with recent regulations. Also I could use the data to call using voip anyway, which is even cheaper.