Can't believe this hasn't been posted already...
EXPEDIT is usually somewhere in the region of £50 but currently they are reduced to just £29. That is a fab price for one of these. Ok, they're really common but they're good strong units, and Habitat sell something that looks very similar for about 10 times the price. Fab for kids bedrooms and simple to build up (or if you're more adventurous you can adapt the sizes of the cubes to make some rectangles!).
Available in birch, white or black/brown. It is only the unit that's 4 squares by 2 squares that's this price, although there were also reductions on other LACK items to match when I was instore yesterday at Leeds.
Stands vertically or horizontally. Can be fixed to the wall if you've got kids likely to pull it over on themselves or if you want to use as a room divider. Holds 12" vinyl & A4 files.
Available in-store at this price at all Ikea branches except Edinburgh & Cardiff (I think because they're franchised?)