Has anyone came across or used a portable printer before? The models available are all quite expensive and I guess that is a combination of them being both quite a specialist item and it requiring expensive components. I'm keen to invest in one of these for work purposes but not sure about some of the reviews online. Has anyone used one of these for work documents? I need one that will fit within a standard laptop rucksack so probably not more than 40cm wide or so and preferably something belong the $300 mark.