I decided to try one of the DNA test services now available. Basically they give you a way to compare either direct male lines (the "Y" chromosome), or female lines (mitochondrial DNA)
So, if you are the Deegan son of a Deegan son, of a Deegan son, etc. we could see if potentially we have similar "Y" chromosomes, and therefore a common male ancestor.
Basically MEN with the D*g*n name are candidates.
I've already sent my sample (a cheek scraping, NOT blood) to this service, and if you choose to do it, they would tell us if we had a match. They can only make statistical estimates. A perfect match in their test would suggest a 50% percent probabilty that we had a common male ancestor withing the past seven generation (less than 200 years).