When did they say you would hear by? Normally at the end of the interview they would give you some indication of what the next step might be and possible timings etc. What type of company was it? Some will take longer than others in arranging second interviews (and with it now being half-term maybe some staff are off who need to be involved in decisions)??
They just said 'we'll let you know' at the end. It's for an educational establishment and the need someone to start ASAP which is why I think it's odd that they haven't made a decision yet - or maybe they have but just haven't got round to telling me that I haven't got it - in which case I will be cross as I'd like to know.