It turns out, mostly skateboarding, videos, teams, and people named Mike.
To find out, I analyzed over 50 interviews from the wonderful skateboarding blog the chrome ball incident. I did this by scraping the content from the site (with python, of course) and then filtering out some common words (stop words) to get meaningful results. I then used Wordle (which is really, really cool) to make tag clouds of the 150 most frequently used words in all of the interviews.
The total word count was a whopping 229,199 words (for comparison). The first round of filtering was pretty modest - I only removed the 186 most commonly used English words. Here are the results (click the photo to embiggen):
Including a slightly larger list of stop words reveals a bit more character:
Amongst the expletives and common skate-slang ('dude', 'stoked', 'rad', 'spot', etc.), the word 'street' (as in, street skating) is mentioned 3 times as frequently as 'vert' (as in, vert skating) - something we've seen before.
You can see the raw data here and here for each stop word filtering. Play with it please!