Take Advantage

Usually 'taking advantage of a situation' comes with a negative connotation, but I believe in something different. There are ways to take advantage of situations in order to benefit you and the people around you (your company, co-workers, friends, family).
I'm primarily thinking about the workplace - join as many committees and extra projects as you can reasonably handle. Do not overwhelm yourself to the point that your job performance will suffer or you can't make a true commitment. But do try something new - join a committee and perform a role that is different from what you do in your day to day job. Learn about a new project or company goal while interacting with people from various departments and various levels. If your company offers subsidies for training courses take as many as you can, making them tie-in to your current role. These things will make you a more well-rounded candidate when you do choose to move forward or move on, and your department and the company will benefit with your increased knowledge, contacts and confidence. If you're in a position where you lead people, use that opportunity to learn and develop as much as possible. Read books on leadership, speak with other Managers/Execs to get tips and hints, and exercise your new knowledge on your direct reports (of course being careful not to hinder their experience!).
If a friend is starting a business, offer to help her with the promo, design or budgeting. Use your skills and get higher level experience (think creating the company budget vs.monitoring a small portion of it), to help her and yourself. If there's a specific skill you're looking to develop, apply to be a volunteer with one of many organizations - you can contribute to an important cause at the same time.
Often we find ourselves in less than perfect situations with one or more things in our life. While you are in that job, relationship or even city - take advantage of all the opportunities that are hidden within.