moBlog is a mobile blogging application for Windows Mobile (WM) devices. moBlog currently supports Blogger, Wordpress.com and Live Spaces. Support for LiveJournal and MovableType/TypePad is also on the cards.

moBlog is optimized to run on WM devices using minimum resources. It is an application that you can use in off-line mode, where you can do your writing and editing disconnected to the net. A connection is only required when you initially setup your blogging accounts and when you want to update your blog with the new content. moBlog allows you to save the blog posts locally while they are still being written and edited (I do understand that sometimes you may not be able to finish a blog post in one go), and once it is published, the local copy is automatically deleted from the device in order to free up the storage space (storage on devices are scarce).

for more info check the developer website