While researching my answer I found the gems below to be amusing.
Hope you do too.

"I used work in a hotel bar in Ireland, while there I made 100's of
Irish Coffees. The key is not to have the cream fully liquid or fully
whipped, somewhere is the middle is best. Pour the cream on to the
back of a hot spoon at the side of the glass to insure the cream
floats!"

"NO! NO! NO! You don't whip or beat the cream at all! The trick is to
get the fresh cream to slip over the spoon onto the coffee. The sugar
seems to be the secret - it increases the density of the coffee (or
something) so that if you do it right, the cream just floats just
right.
I don't know how many so-called "Irish Coffees" I have sent back in
the US 'cos they used WHIPPED cream!
And yes ... I am Irish ..."

http://www.barkeeper.ie/page.asp?menu=104&page=492
http://www.tablehopper.com/archive/2..._01_index.html
http://mylifeasareluctanthousewife.b...coffee_07.html
http://www.thebuenavista.com/irishcoffee.html
http://www.fantasy-ireland.com/Irish...e-recipes.html
http://www.sciencebuddies.org/mentor...hem_p021.shtml