I have a stop watch on the dash - whenever I go into IMC I start the stop watch and when I pop back into VMC I stop the stop watch. Keeps me pretty busy when I am flying through broken CU. After a 3 hour flight I take the accumulated time in IMC off the stop watch (ie 1 hr 3 min 25 sec) and write it up in my log book.
Isn't that what everybody does?
Sure it is!
Dr 
Oh dear, has it really come to this? If we can't even get common agreement on how to log IF time, what hope is there of getting the important stuff right!