Check whether your camera instigates mirror lockup when you set it on one of the delayed timer modes. On the Sony if you use the 2 second delay timer, i.e. you press the focus button to focus, then press it down further to take the shot, the mirror will lock up then two seconds later the shutter will open and the shot will be taken. The advantage of this is that you can get away without using a remote shutter release cable, as you can take your mitts off the camera in the two second gap. The remote release cable is always going to be preferable though, but at least you can try it and see what the fuss is about re: mirror lockup.