Car only came with one key (any thoughts?)

[Squiggy]

Hi guys. I bought my first BMW recently (2003 X5 4.6is) and my poor little car (or should I say TANK) only came with one key. I think it was a bank repo.

I'm not 100% comfortable only having one key as you can imagine. I'm also not 100% comfortable knowing someone out in the world has at least one and maybe more than one key to my car.

Any advice welcome.

Ideas I had:
1. Just have a spare made. Call it good (do I do this at the BMW dealer?)
2. Have the ignition replaced or re-keyed? If so how much money I wonder or is this even really practical?

Thanks,
Squiggy