Parody is a humorous imitation of a person, event, song or serious piece of writing. I have a great time when I use this technique in a presentation and so do the audience members.
The way I use it is to change the words of a recognizable song. I get the audience members to sing along with me by putting the words in their handouts or giving out a song sheet. (The latter method keeps the whole segment hidden so I can surprise them.) I get the words to customize the song from my pre-program research.
Simply take any recognizable tune, change the words, and sing it yourself or get the audience to sing along.
*Parody is generally protected from copyright infringement, but get competent legal advice before using this technique.