If you own or use one of the above devices, and have a LiveJournal account, have you considered using the former to update the latter?
May I introduce pocketlj! :-)
It's a feature-packed LiveJournal client for AvantGo (a content browser for handheld devices).
It allows you to be able to record entries on your device offline, which will then be sent to your LiveJournal when you sync your device. (It also has limited-but-expanding support for online posting.)
If you're interested, have a look at the PocketLJ Website! :-)
(These shameless plugs will be the end of me!)