Just wondering if anyone has tried/ suceeded to learn another language to a good level i.e. fluent ?

Just bought myself the Michel Thomas Spanish dvd set to give it a go, as I would like to be bilingual (sp) to possibly help with my work (self employed surveyor) as there's plenty of oppurtunities in Spain and obviously speaking the lingo would be a massive advantage.

Anyone done this with any language for any reasons ?