RTUR.NET have designed a cool theme for BlogEngine.net (If you access a blogengine blog from a mobile device , blogengine will use this theme if you set this as the default mobile theme).
Home page will display the categories and then the post headings of the selected category, and then the post.
Using this theme you can ever Login and post to the blog if you are the administrator or editor of that blog. This theme look very very good if you are using iPhone.
You can download and read more about this theme here
Am using the default mobile theme in the BlogEngine installation which look good too. try http://geekiest.net from your mobile phone