I've always wanted to blog about something, just for something to do. So today I thought "Why not make a blog about Fantom?" ... Would this be okay for me to do? I was thinking about just blogging about how to do stuff in Fantom/adding code samples to my blog etc

Blogs and link love are always welcome!

Why should the creator of Fantom have to give you permission to speak/blog?

Besides Fantom could use some positive exposure ;)

What site will you be using for the blog? I'd being willing to do something similar myself, but I don't know which site would allow me to get any traffic.

You can add any blog feed to javablogs.com if you talk about Java-related stuff, which Fantom is. If your post looks interesting to people, you'll get clicks.

If someone really finds it interesting, they might post it elsewhere, like DZone or Delicious or wherever.