The fact that Leonard sees Mandy (Melissa Tang) regularly also doesn't sit well with Penny, and their wedding night is ruined.

CNN: 'Big Bang Theory': Penny and Leonard say 'I do' �� now what?

When IBM's master inventor Mandy Chessell was at school, she said she had "missed the memo which said that girls don't do maths and science".

BBC: Women and tech: Why don't girls want to be geeks?

"We don't think it's a gimmick - it's a taste of the future, " says Mandy Minichiello, marketing manager for Tesco.com.

BBC: Tesco try out virtual grocery shopping at Gatwick Airport