This is a common question at the moment, there is a new product being tested in Malaga at the moment for high speed wireless internet called wimax, however it is a little way off. The 3G cards from (dare I say it) MoviStar and Vodafone are very good but still not as hot as a true line.
I have posted it before cause I think it is a wicked idea and helped me with my awful line at home http://www.onspeedspain.com crunches the data down so it travels up and down faster meaning that you can have a slow connection that seems to run a lot faster than it is because it only sends the data that is needed.
Hope this helps?
Steve
http://www.easy-info.net