Just stumbled upon this offer directly from IBM. There is also another offer for free memory with System-X.
Buy a BladeCenter E or a BladeCenter H and a Minimum of 4 Blades or a BladeCenter S with a minimum of 3 blades (minimum configuration applies) before June 30th 2009 and IBM will provide the chassis for £1. Not only that, but opt for a redundant pair of Bladecenter S's unique shared storage controllers, or two Nortel switches, and get one free of charge!
For more details on the IBM BladeCenter portfolio visit Blade Center
Or contact IBM on 0870 010 2516 (09:00 to 17:00 Mon - Fri) or email us to be put in touch with your local reseller.