Yeppers...that be an Umbilical hernia.... I lived with mine for at least five years and had it repaired a year before PC surgery.
Reason I had mine repaired is that I bumped it real good and it hurt like hell for a couple weeks.
If you read up on it you'll see that there is a SMALL chance that some intestine can get pinched and turn gangrene and is a much larger surgery. My surgeon says you'll know it if it happens...
Couple of pictures and additional info here:
http://en.wikipedia.org/wiki/Umbilical_hernia