In addition to psychology, I also teach US Government. I have a number of students who are learning English and I will utilize my own childhood experience of "School House Rock" on DVD as a subtitled visual tool to help them learn about various aspects of the government. One pernicious song for me is "The Preamble." You can view a copy on YouTube here. The sad and bizarre point I am making is that when I show this, I cannot get that darn song out of my head for days. In fact, as I sit here writing this, it has come back. Grrr.
As it turns out, there is a name for this phenomenon--it is called an "earworm." 
In March, 2008, Radiolab did a show examining and explaining why the experts thought they occurred (included Oliver Sacks and Diana Deutsch). In June, 2008, Radiolab did a show on how people reduce these irritations. I am pleased to know why they occur and some strategies for reducing them.
- Wikipedia Entry on Earworms
- WebMD Entry
- SFGate Article
- University of Cincinnati article on sources and possible explanations for a business college article, it was awfully full of science
