You can save the text of an entry as a text file.
I've been meaning to implement saving an xml file, which will save all the other variables/parameters (music, tags, etc.).
it's just a matter of writing that in, not a difficult piece of code, just need to find my rountuit...

Hmmm..."post-to-all" button...there's an idea...

What I really think I need to implement, besides adding blogger posting, is downloading entries, so one can edit them in xpostulate, and repost them.
At this juncture, it just sends them up, of course.

Perhaps I should look at this MacJournal.
A friend of mine here, catness, and on DW wrote a client in php that crossposts, too. I think the gui was not as "intuitive" or "user friendly" as xpostulate, but I believe it had more features.
I had trouble installing hers, though. (so I wrote my own in tcl!)
Criticism, comment...constructive feedback, either way.