He is someone in the valley with a big ego. He is outgoing and speaks fast but in a very organized way. I am a big fan of his blog: http://blog.pmarca.com/ though he stopped updating it for months.
He said that a successful entrepreneur has to hire a killer architect, watch closely on the change in the technology industry. He said it's hard to be a person who can both building the company and run the company. He said the silicon valley used to be a high-tech driven company but now turned more into consumer driven. He said the timing is very important.
One thing surprised me is his wide knowledge beyond technology. He is interested in media, and once spent a lot of time on reading the media history. He is also interested in financial service industry, and predicts to see a big change in the next 12 to 18 months.
I always respect smart people who work hard, and he is definitely one of the few.