Ok, after fiddling around with a few different blog utilities for my mobile phone/PDA, I think I've found one that offers all the features I was looking for. It's a simple program from Normsoft, called hBlogger. It supports uploading photos and text and it supports quite a few different blog web sites. Normsoft is probably better known for their PocketTunes utility for the PalmOS - a handy little program for listening to MP3s on Palm OS devices (such as the Treo).
I can't guarantee there will ever be anything worth looking at here, especially if the first two test messages (below) are any indication of future content. But feel free to poke around.