BDB - Thanks! I did look into an iPhone cake, it would have been right up his street. It was a little bit complicated for me to make by myself and on limited time so I had a look online. Some companies have made excellent ones but considering most of it would have ended up in the bin it would have worked out to be very expensive.
Cake was completed at lunch but I had a slight disaster. With the warm weather, the buttercream filling got a little 'fluid'! I didnt have time to let it set a little bit so the top half slid about a bit when I put it on! It's resting in the fridge at work to hopefully set it, although the heat in my car getting it there almost led the top half to slide off completely. Eek!