Might be able to find services that publish posts from emails. Then it's just a matter of writing an email from your phone.
Posterous[0] used to do that and it was good. Then they sold their souls to Twitter and, obviously, all the good went away after a year.
(one of the founders then launched Posthaven[1] but a) fool me once, etc., and b) he's an intensely problematic lunatic.)
P.S. Not affiliated