Well, I'm struggling with the whole friendship thing as well, but one thing I have learnt: scratch busy from that list. If you want friends, you need to make time for them. That is the first step.

Also, from experience, I've met some wonderful people on the net. But then again, it probably depends on where you meet them. I have had more luck with sites like last.fm (I like music, your interests may differ), tumblr or discussion forums than dedicated sites. It's probably that you can find people with similar interests and worldview easier that way. However, online friends can never replace someone you can meet in the flesh, so don't rely on this. Reach out to people around.

Oh, and one more thing. Even if you make the first step, tell yourself you won't feel pressured into getting close with a person if you're not enjoying their company. It should make it easier to reach out without being too picky. (Are they smart? Do we have much in common? Will they be downers? No way to learn if you don't try talking to them!)