Since it already exist a solution for the wordpress.com-bloggers (https://m.wordpress.com), I hope that it might come in future releases even for us with the selfhosted wordpress blogs.
Hopefully some one else will have better answers for us that don't have iPhones :-)
Just a note. OnTheRoad.to, which is a new online travel diary, would allow you post your notes and pictures directly through your mobile phone. (And you can get a real-time "trip widget" of this diary, that would fit to your wordpress blog.)
OnTheRoad.to has an iPhone app, Android app, or you can send out your posts via email or SMS/MMS. It comes quite handy while traveling. (And with the phone apps, you can forget about the data roaming when going abroad, they both have an offline mode.)