Whats a good title for a story about 3 kids growing up to become bank robbers in the 1930's?

I could just say call them 'Lucky', 'Baby' and 'Butterfingers' but it really depends entirely on the characters you have in mind.

Are they all boys, or is there a girl?
Where did they grow up - the type of town - a milltown- a big city - rural America - the physical landscape - were they well-off or impoverished, were their parents good, drunks, religious - etc?

All these factors are important background on which to build characters and ultimately name them. You may not even want to mention their childhoods etc in your book or film, but building a back-story for them will give you a lot more clout as a writer and your characters will be more consistent and believable because they have a 'past' that governs their present. If you do this, the right names will come to you because they are more like real people. I hope this helps :)

Hoodlums!