I worked remotely from Europe for about two months last year, and spent a few weeks in Spain. I just got a travel visa. It didn't even occur to me that it would be an issue. I think they're more worried about you overstaying your visa than working on your laptop. Just make sure you have a return ticket, or a train ticket out of every country you visit. I got grilled by the immigration guy in Ireland because I bought a flight to Dublin last minute and didn't have a flight back out. I'm not suggesting anyone knowingly break the law, just sharing my experience. Nobody gives a shit what you're doing on your laptop at Starbucks.