As far as I know and I have read, the only way you can get that going is by pressing half way down before you take a photo with the flash on and holding it. Otherwise there is no way to use the flash like a torch as of yet.
All hope is not lost. Try slamming one of these on your phone and giving it a try . The top one will be the best one to use, though I dunno if that one will work. If not, try one of the other ones - I can guarantee it'll work - it does on my K800i