It's worth it if you get in on the right stocks. What you want to pay attention to is what the company is doing, what the companies plans are, quarterly earnings, and how external issues effect that company. For example, if you invest in McDonald's, and it comes to light that their food causes cancer, their stocks will drop. Kind of a dumb example, but you get the idea.
My advice would be to get into it for the semi-longhaul....with a company that is doing well, and you know will be doing better a year or so down the line. I bought Apple Stock at $100 per share a few years back, and it's now almost at $358 per share.
It's all a gamble, but there are some companies you just can't go wrong with. Some family members of mine invested in Ford and BofA when the market took a dump. They doubled their money in about 7 months.
Oh, and you have to BELIEVE in the company. I almost dumped my stock when Apple announced the iPad....but I held on to it. It was a good idea.