I tend not to write reviews usually, but I'm making an exception because I have finally found a cleaning company that has actually heard of the internet!
I use maid.ly as and when I need to (ie. parents coming to visit!). I book them, select a time/date and pay all through their website. The whole process takes about a minute, and works on my iPhone. This makes me very happy.
Also, they have always been on time, are friendly, and much better at cleaning than me! Recommended!