Almost 15 years ago, I started to teach IT. Ha, in the beginning, it was how to use DOS, later Windows, Word, and all that stuff. And it always struck me how there were three kinds of students.
A few of them would sit back and say: I don't understand anything. I'm stupid.
Most would just listen, learn, and do the exercises as told.
A few would listen, learn, do the exercises, and then do a lot of other stuff, thinking: What if? Can this be done?
Those latter were super-users. They would learn much more, and get much farther than the other students.
How can you use this in your online business?
You buy a domain (maybe even an info domain, they are very cheap), and you throw up a blog. Then you're ready to test everything new, you learn about, or just think “what if…”
One of my friends and colleagues has such a blog. Sometimes his tests give a nice result. Sometimes nothing happens. The most important is that this site should not “officially” be yours. You don't want people to come years after and knock you over the head with your early tests.
PotPieGirl tells how she always puts a new ClickBank product on her test Squidoo lens. If it works, then it'll get a lens of it's own. If it doesn't, well, then nothing much was lost.
When I say a blog, it's because a blog is so easy to set up. You can just as well have an old-fashioned HTML page, or use a CMS, or whatever feels best for you.
But having a place to test things out, even crazy ideas, is not only fun. It could make you a lot of money, too.