We've featured a simple IKEA LEGO table before. This variant uses the $69 Expedit 2 by 2 bookshelf to build an area that encourages collaboration and also gives you plenty of storage space to store recent creations.
The concept would work with any open bookshelf, but the Expedit seems particularly well suited since it's deep enough to easily fit a LEGO baseboard. Hit the IKEA Hackers post for full details.
LEGO Playhouse [IKEA Hackers]