Saw in the current edition of Amateur Photography in the Park Cameras advertsising bit, you can buy the Sigma 55-200mm lens for £49.99 ( http://www.parkcameras.com/643/Sigma-55-200mm-f-4-5-6-DC--Canon-fit-.html#bundles
) with any Canon EOS body.
No-one really likes bundled kit lenses and Park Cameras are selling the EOS 550D with kit lens for £709.99 but the body only is only £629.99. Thought this would make a nice offer, plus if you quote Amateur Photography (saw this on same page) you can get a free Cokin Filter Holder when you buy any DSLR and Cokin Filter.
On top of that, you get cashback with Canon on most of their DSLR's (think it's £50 with the 550D lens kit, so might differ with the body only).
N.B. Offer is not quoted online so you can probably receive it by phone or instore.