Hmmm.  All these blogging sites are a little different from one another.  Here in Google-territory, the creation of a new post presents you with a blank editing screen -- and no context within which to compose.  Elsewhere, it's more Wiki-like, and you simply insert text below (or above, if that's how you roll) all prior entries.

No matter.  They all work, and after some floundering perhaps I'll settle on a single one.