I have a personal logo, for no good reason. It combines my initials (DMM), my interest in alchemy, my enjoyment of change, my affinity for the positive connotations of fire, and my red hair.
Each component of my logo has at least one meaning:
This is both my first initial (the Greek character delta, for D) and the alchemical symbol for fire. The delta is also a symbol for change in science.
This is both my second (and third) initial and a more conventional depiction of fire.
This is an exclamation point, which symbolizes action and being emphatic and enthusiastic. The lower dot also acts as a period, to go with the initals: D. M. M. It can also be seen as a head, allowing "fire above head" to symbolize my red hair.