Here's another explanation, from the Tombstone FAQ:
http://members.cox.net/tombstone/faq.html
What is the Meaning of "I'm Your Hucklebery?"
In Days of Destiny's "Mass Lynching," It is claimed that on August 28th, 1885, 9 people were taken by a mob intent on performing justice, and hung at a tree close to Tombstone. One of these soon to be lynchees was a gambler known only as "Joe," and at 3 that morning, four men burst upon him dealing cards, and leveled guns at him. Joe responded quickly, saying "Well then, I suppose I am your huckleberry!"
As Joe was dead within hours, no one could figure what exactly he was talking about....
I'd say that Barbara LYFORD (<btlyford@sbcglobal.net) basically answers the question, though:
"Huckleberry" was commonly used in the 1800's in conjunction with "persimmon" as a small unit of measure. "I'm a huckleberry over your persimmon" meant "I'm just a bit better than you." As a result, "huckleberry" came to denote idiomatically two things. First, it denoted a small unit of measure, a "tad," as it were, and a person who was a huckleberry could be a small, unimportant person--usually expressed ironically in mock self-depreciation. The second and more common usage came to mean, in the words of the "Dictionary of American Slang: Second Supplemented Edition" (Crowell, 1975):
"A man; specif., the exact kind of man needed for a particular purpose. 1936: "Well, I'm your huckleberry, Mr. Haney." Tully, "Bruiser," 37. Since 1880, archaic.
The "Historical Dictionary of American Slang" which is a multivolume work, has about a third of a column of citations documenting this meaning all through the latter 19th century.
So "I'm your huckleberry" means "I'm just the man you're looking for!"
Now ain't that a daisy!
The story about Doc's grave is correct - his body is buried in what is now the suburb of Glenwood Springs, Colorado, which has expanded to the area around the cemetery. Winter weather prevented the hearse cart from making it up the hill to the cemetary, so they buried him at the foot of the mesa below Linwood Cemetery.
Here's something odd: Doc was played by a lot of different actors in TV and movies over the years - Cesar Romero, Martin Landau, Victor Mature, Kirk Douglas, Jason Robards, Stacy Keach, Dennis Hopper (I liked Val Kilmer's performance, but still think Dennis Quaid turned in the best performance in "Wyatt Earp")...
Who played Doc in more different TV shows than any other actor? (It is not someone you would probably associate with the character.)