I'm in the same position. I used to hide my spare apartment door key on my apartment patio (but would still have to get someone to let me into the complex, as I had only one key for that) but due to ongoing construction until March, I no longer have an outdoor space to store my duplicate apartment door key.
The other day while picking up an Amazon package at my local Safeway, I saw a Key Me kiosk. In addition to making copies right there, if you register yourself, you can go to any kiosk and log in and get a key created from your electronic record.
I don't know what the odds would be of a breach, though I assume that the record doesn't include an address.
My keys say "Do Not Duplicate," but I did some research and found out that in California, except in Los Angeles, that means nothing -- anyone will duplicate the keys. In fact, locksmith groups say that that language creates a false sense of security.
I'm sure I'll end up doing this, just for peace of mind, as I have no friends or relatives near to hold duplicates for me. They do car keys too, which I also plan to have done (my car is old and doesn't have a fancy key).
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