There is a nice technique which is used to convert 0 to #Missing.
If we have many blocks in the cube which are 0 and we want to convert them into #missing so that we can use Clear Empty block to remove unnecessary blocks.
member = member * member / member;
it will make 0 #missing;
then clear empty block.
I remember reading Edward Roske's post on this a while back: http://www.network54.com/Forum/58296/thread/1209018907/Replace+0+with+%23missing+Calc+Script
Interestingly, you will note that multiply and divide process was slower than an IF test. Every database is different, and benchmarking is a really, really good idea.