Cheap as chips, £1 each delivered basically, plus come in different colours:
Black - http://www.7dayshop.com/catalog/product_info.php?products_id=103945
Purple - http://www.7dayshop.com/catalog/product_info.php?products_id=103947
Amazing Deal - 2 super-bright handy keyring torches for this awesome price! No more fumbling in the dark with this ultra compact and very handy keychain torch. Features a VERY powerful LED single bulb which is powered by the 2 included lithium coin batteries. LED bulbs offer really superb performance and greatly extend battery life. This keyring torch is supplied with metal rings for key or keyring attachment. Simply squeeze to activate and use the micro switch to lock on if needed.
Please note that this little torch is really VERY powerful and we do not recommend staring directly into the beam !!
This 4cmx2.3cm unit houses 2 x CR2016 lithium coin batteries and these can be changed by the user if and when they run flat. To do this you will need a small cross-head (Phillips) screw-driver, a steady hand and a little bit of patience too !!