Great tip - thanks. I use Play.com for DVDs and games a lot, but didn't realise they sold Lego.
Having checked out the site, the prices look good. At worst they charge the same as Lego shop@home, and at best they undercut the S@H prices by a significant amount. Plus there's the major bonus of no delivery charge versus £5.25 from S@H. I picked up the Corporate Alliance Tank Droid for about 15% off the S@H price plus no delivery charge which is a good deal, although they don't currently have stock (marked as "preorder" with release at the end of August). Other newer sets are also "preorder" status.
Some of the older Indy sets are a particulary good deal. Temple of Akator is a third off at less than 50 quid, and Temple Escape is also heavily discounted.
They've got a toys section now. Lego is no longer under gadgets. But depending on which way you click through to the Lego section, you can see a complete list (with all new sets on preorder) or just sets available now.
EDIT: also just notice the cashback for toys on Play is now only 2%. Still better than nothing.