I found a post on google's official blog that is very interesting and helpful: what they look for in employees. As one of the world's most successful (if not the most successful) knowledge-driven companies, this is very instructive:
There are many factors, of course, but we primarily look for ...
... analytical reasoning. Google is a data-driven, analytic company. When an issue arises or a decision needs to be made, we start with data. That means we can talk about what we know, instead of what we think we know.
... communication skills. Marshalling and understanding the available evidence isn't useful unless you can effectively communicate your conclusions.
... a willingness to experiment. Non-routine problems call for non-routine solutions and there is no formula for success. A well-designed experiment calls for a range of treatments, explicit control groups, and careful post-treatment analysis. Sometimes an experiment kills off a pet theory, so you need a willingness to accept the evidence even if you don't like it.
... team players. Virtually every project at Google is run by a small team. People need to work well together and perform up to the team's expectations.
... passion and leadership. This could be professional or in other life experiences: learning languages or saving forests, for example. The main thing, to paraphrase Mr. Drucker, is to be motivated by a sense of importance about what you do.