Fred Gratzon at the The Lazy Way to Success has some great advice, hard won personal experience, in his post Which Passion Should I Pursue?:

My advice would be to pursue them all until one starts to show a little promise. At that time, feed that new sprout with more attention. In other words, where there’s smoke, pour gasoline. If your fledgling enterprise ignites, you will naturally be swept up and it will immediately consume all your energies and stoke your passions. It can be a scary time because you realize you will have to abandon your other pursuits to do justice to this one. But, on the other hand, it is exhilarating to be involved with something that is taking off.

Nature figured out for me what I should do with my life...Just pursuing an interest is enough. If it has potential, then that potentiality will show itself soon. If it doesn’t, then you know you need to make a course correction.

While this may seem obvious for some of you, for those of us in the thick of making our own way it's a godsend to have this kind of guidance from someone who has lived it.

I keep a list of all things I'm interested in doing, on one level or another, and when a "slot" opens up in my bandwidth I try to figure out the best direction to follow. And the adventure that is my life and my business takes another (often unexpected) turn.

And if you aren't familiar with Fred's blog, do check it out. It was one of my favorite discoveries on my Blog Bliss day last week.