This is what I've been working on for the past several months. It's a combination of a custom J2ME based mapping client, weblog service and location alerting system. It's being sold to carriers, not to the general public, but you can play with the public weblog site above. This is the piece I developed. It still needs a lot of hardening and ever more features need to be added to keep up with the TypePads of the world, but in general it's your standard weblog service, but with the integration of location information and maps.
I have to admit... I'm a sucker for these type of phone applications.