Microblogger allows you to post quick comments to your readers, without need for an account (as the twitter etc plugins do) - even from your mobile!
[STEPS 2 TO 4 AND 9 ARE OPTIONAL - use only if you want the mobile UI!]
1). Extract the zip to a temporary location on your disk.
2). Enter the
mobile directory. Then open
index.php in a text editor.
3). Edit lines 3 to 5 to reflect the information of your wordpress holding database.
4). Copy index.php to a place on your fileserver. Bookmark this location on your mobile phone.
5). Copy the
microblog directory to
[blog root directory]/wp-content/plugins.
6). Activate the plugin from the word press 'plugins' page.
7). Edit your theme, to include
<?php do_action('showmicroblog'); ?> in the position of your choosing. Maybe the left sidebar? (This step ultimately depends on your theme, so you will have to explore your own situation here - good luck!)
8). Edit the options in the 'Microblog' section of the admin area, maybe make and upload your own microblog/recent activity banners then reference them here?
9). Pay particular attention to the 'Pin' setting if you want to use the mobile UI.
10). Microblog away! Again, any feedback will always be welcome on my blog or at firstname.lastname@example.org