Forum:Medusa work and Guardian Sphinx Question

If I special summon in my opponents turn, a Medusa Worm or other monster that has in it's effect "Once per turn you can flip this card into face down defense position" for example with giant rat or broken blocker, when it then becomes my turn can I activate the effect, flipping them face down, then immediately flip summon them to gain their other effects effects? Thanks. Adam Gough 15:06, 28 September 2008 (UTC)