After studying this thread, and looking at Amazon reviews, I went and ordered this one:
Arrived next day.
Haven't tried it on a trip yet but it's about 1/4 the weight and space of the domestic power strip I've been carrying.
With 2 x 2A USB ports , 2 x 1A, and one universal socket, it should be good enough for laptop and phone/tablet/kindle/powerpack charging.