I was at Harrow Branch of Jessops yesterday and they had the Sigma 18-200mm OS (optical stabiliser) lens available in both Nikon and Canon fit for £199. This is an extremely good price (about £80 cheaper than anywhere else).
The Nikon version has the HSM motor built in so works perfectly with my Nikon D40 (and will also work with D40x and D60)as well as my D90
The Nikon equivalent version of this lens is £549 which is nearly 3 times as expensive as the sigma. The sigma lens has had very respectable reviews. see here for example http://www.dpreview.com/lensreviews/sigma_18-200_3p5-6p3_os_n15/
The offer is INSTORE ONLY.