Professional weekend work



I am currently working in IT. I am fairly new to my career and am enjoying it so far. However the financial burdens of London do not allow me to save much as I would like. Does professional weekend work exist? If it did, I suppose it would exist in London however Google searches are not really helping me. All returned results provide generic recruitment site results. My current contract states that I can not be paid for any overtime.

I am looking for IT related weekend work in London. Does anyone know of any firms, big or small, that hire people on a weekend or casual basis for IT work?