Since I'm gonna be using this a _lot_, this seems to be a good place to start.
The blogger for android has a dead simple, yet attractive interface, and provides access to the basic blogger posting functions. You can write posts (though no option to format that text... at least bold&italic would be nice.), add tags, attach pictures -and for some godforsaken reason, your current location.
You can publish & save as draft (I managed to lose a post tough), and edit previous posts. Overall it is a nice app, and I kinda like it.