Wow. If you're a PhD in a subset of some science field, click away now. Tim Ferriss, best selling author and life coach has posted a blog called, "The Top 5 Reasons To Be A Jack Of All Trades" This post has really had impact for me since I deal with this issue constantly. More directly, being "good" at many things often makes for awkward answers to "what is it that you do?"
Here's the wrap up quote from the author.
Don’t put on experiential blinders in the name of specializing. It’s both unnecessary and crippling. Those who label you a “jack of all trades, master of none” are seldom satisfied with themselves.
Why take their advice?
Here is a description of the incredible Alfred Lee Loomis, a generalist of the highest order who changed the course of World War II with his private science experiments, here taken from the incredible portrait of his life, Tuxedo Park:
Loomis did not conform to the conventional measure of a great scientist. He was too complex to categorize—financier, philanthropist, society figure, physicist, inventor, amateur, dilettante—a contradiction in terms.
Be too complex to categorize.