I avoid the topic altogether, and 'run my own biz with computer and internet stuff' is usually the best fit for me to. Otherwise they get lost quick, and or they get inspired enough to pick my brain to no end.
Have had this convo many times with other marketers/media pros, most agree that dumbing it down is usually best. However in your case it sounds like you want to whore your services to whoever asks - so just ask them for their creds/line of work first. Or if they ask you just say 'I help business owners grow, in many many ways' - that will open you up to anything/everything.
EDIT: ^ Side note - My GF's brother actually does program/fix/work with elevators, makes good coin too.