Ikea, the timewarp shop, as far as I'm concerned - you 'pop' in and hours and hours later find yourself bedraggled and worn out, burdened under way more than you ever intended to shop for. But, especially if you're in rented property, I always find stuff that makes life easier at home, especially on the space efficiency front!
Anyway, they have three children's lamps reduced at the moment:
Each of these is reduced from $16.99 to $9.99.
Apparently they can be used with energy saving light bulbs, and some of them can be mounted in different directions - the moon for example.
They do produce a bit of heat, so should probably not be mounted in reach of children or near curtains, but they are pretty cute and for the price it's probably hard to go wrong. If nothing else it works as a mounted night light and brings a bit of decor to a child's room without breaking the bank.