I grabbed a glass table-lamp from IKEA that I has been lying around our house, unused. I cut some wrapping paper to size and sticky-taped it to the outside of the glass and put in a globe.
After the usual excitement that follows a change in their surroundings, the boys went to sleep by the light of their new lamp. I might eventually replace the wrapping paper with something a bit more "boyish" (Mr Sociable tells me that the paper is too girly), but I don't think I'll bother to buy a "proper" night light. This one is working well!