Officially, my title is a string of semi-applicable adjectives, followed by "Software Engineer".

Unofficially, I use many different descriptions, depending on the audience:

• I sit in a small, fabric-covered box, type all day, my hands are soft, and have never done a day's work in my life, Mum
• I work with computers
• I work with web sites
• I'm a programmer
• I'm a software engineer
• I'm a (string of adjectives) software engineer

I never mention languages or operating systems. If they are that interested, I point them at a resume.