Great price! Come in many different designs, some quite crazy! Both 0.6l and 1.0l bottles are £3.99, which is fantastic! Can't get them for less than £10 generally! Some with the active sports top and some with the screw top.
The Original Sigg bottle
Unbreakable light weight 0.6/1 litre bottle
Unbeatably light, tough and leakproof
Made from lightweight aluminium, Hygienic interior coating alleviates odourshttp://www.sigg.com/uk-shop/index.php/en/design.html