For instance, many 8-letter names can be shortened to various nicknames. "Angelina, Dominick, Julianna and Percival" and can be shortened to "Lina, Nick, Anna and Perce," or to "Angie, Dom, Jules and Perry," or even to "Angel, Nicky, Juli and Percy."
Personally, though, I think "long" starts at 9 letters. :) Over 200 9-letter names have popped up among the 1,000 most popular names in the U.S. since the year 1880. Some of these popular 9-letter names are:
Christina, Gabrielle, Henrietta, Katharine, Priscilla
Slightly longer than the 9-letter names are (of course) the 10-letter names. Over 50 ten-letter names have reached the U.S. "top 1,000" since 1880. Some of the more popular 10-letter names include:
Alessandro, Florentino, Montgomery, Rutherford, Washington
The longest names that have ever ranked nationally are 11-letter names. Specifically, there are 7 of them:
Christopher
Constantine
Encarnacion
Margueritta
Maximillian
Miguelangel
Of these, Christopher was the only one to rank in the top 1,000 as recently as 2006.
Many other (non-ranking) 11-letter names exist as well. These include Alexandrine, Alexandrina, Anunciacion, Apollinaire, Aristophanes, Bernardetta, Caoilfhionn, Chiranjeevi, Chukwuemeka, Fionnghuala, Giovannetta, Kimberleigh, Marcellette, Marcellino, Mavourneen, Maximiliano, Sacheverell and Tighearnach.
Are there longer names out there?
Sure. In fact, here's a list of 12-letter names: Aleksandrina, Buenaventura, Chandrakanta, Christabella, Christabelle, Christophine, Clytemnestra, Hermenegildo, Konstantinos, Massimiliano, Maximilienne, Michelangela, Michelangelo, Philadelphia, Purushottama, Scheherazade and Themistocles.
If you'd like a name that's even longer, you could try either combining two shorter names (CaitlinAnnette) or embellishing a pre-existing name with a fanciful prefix or suffix (Michelangelina).

