An idrop is when you are on your iphone and the call gets dropped. This is meant to be a slang term, across cell phones. So even non-apple phones can have an idropped call.
I was talking with Amy on my phone, and my phone call idropped" Another use would be with the new Apple iPhone v4. They drop calls when you touch the outside edge. In that case it could be used in a sentence like "When I am on my new iPhone v4, it iDrops calls because I touched the rim of the case in a certain spot." "Yes, my cellphone idrops all the time
Accidental dropping of an iphone
*iphone falls out of pocket*
That's an idrop!