I usually change my title depending on who I am talking to.

Someone well educated who understand software should know what being a "software engineer" entails.

Talking to my mum or someone that isn't technical, I am a "computer programmer" as its something I think they will understand a lot more easily.

Or if the conversation is more casual say a random person in a pub, then I will even say I am a "computer nerd", as I think it brings you to their level a bit more and shows you don't take yourself too seriously.