I normally think of the term blog as being a web site of dated entries. As a noun, you can have a blog. As a verb you can blog (eg post) something to it.

It would seem there are people out there using the word blog to mean what I would normally call a blog post:

I’m back, starting with an apology for the lack of blogs over the last few months.

— Garry McGhie, V/Line

Not to single this instance out, because I’ve seen other examples of this use around the place, too. But it just doesn’t sound quite right to me.

Wiktionary / Dictionary.com / Urban Dictionary / Merriam-Webster / YourDictionary.com / Encarta — All these appear to agree with me.