I use triggertrap for the iphone w/ cables. Its the best thing since sliced bread for timelaspe.He asked about the 5DII, not the iPhone.
Ahh, but more importantly, he asked abot time lapse shooting for his 5DII. Which I use my iPhone with trigger trap to do.
As for phone calls, if your doing a really long exposure. Just hit the exposure button, set the timer alarm on your phone, and if you recieve a call, just multi-task into the app and finish the exposure when the alarm goes off.
Or just turn on airplane mode and ignore outside interference. Sometimes a plus when shooting with no distractions.