Actually, when I was in a sociology class I wrote a paper on this. Statistically, there is a slight correlation between race and size. The "Stereotypical" belief is actually correct. That being said the fact is the distributions of size in each race are very different. Caucasian guys have a nice "bell-shaped" curve distribution with the average being around 6.5 and the median being around 5.8 inches. (Note: median is more accurate to "center" of the population.) Black men have a much more linear distribution, which means more black men have a "well endowed" penis than Caucasian men, but fewer have average, and black men actually have about the same number on the "small" side. Overall, east asians do typically have many more men in the "small" area of the distribution. Hispanics have very slightly more well endowed men than Caucasian from the distributions that I have seen.
The funny thing is age actually has a slight "bell-shaped" curve for distribution of size. Men in there 30s show the largest sizes (by .2 inches)
Now we have to examine the fact that size has to do with circumference too. There is a decent correlation between size and circumference, but it is not large by any means. Circumference can often give more pleasure to women than length.
Actually, you ladies may not want a well-endowed male, as statistics show they are twice as likely to cheat on there partners.
Another funny fact is that statistically, gay men have a slightly larger median and average penis size than straight men.