Hey Dave,

What I normally do is just cover the lens very well, make sure it is entirely covered, Then, I set the camera so once it is activated, it is gonna take the amount of pics I need to finish the roll. Then, wait a few minutes for the camera to go off, and it will automatically rewind.

Now, you may be thinking " that sounds like a pain" , well, yes, but, it saves me money. At our Wal-Mart and Rite-Aid, where I get the pics developed, they will charge you full price for a un-finished roll. But, when I set the camera off and it rewinds by itself, they think that there machines messed up and the price goes down. Last time I did this, I got a roll of film developed (single prints), with one hour photo for $4.12