Topher

Provides a user interface under the Reading Settings page for choosing what post element to orderby. Also allows the site owner to chose ASCending or DESCending.
NOTE: Does not allow for arbitrary ordering via drag and drop. This is a simple setting.
<h3>Usage</h3>
Once it’s installed, go to Settings -> Reading section, scroll to the bottom, and choose an orderby and order option.

Default Post Sort

I'm glad I came across this plugin. It does exactly what the title says and nothing more which is what I want in a plugin. 

Simple and straightforward. Great plugin.

Provides a user interface for setting a default post order.

rjl20

Most people don’t need this plugin. Most wouldn’t notice a difference if they had it. All it does is change the default sort order of a WP_Query from posts.post_date to posts.post_date_gmt — that is, sort on the GMT timestamp of a post rather than the local time zone.
Who needs this? People who switch time zones frequently. People running a network installation of WordPress where they want to be able to aggregate posts from all their network blogs easily, and in the right order. I don’t know. I wrote it for FreeThoughtBlogs.com, so their “most recent posts” sidebar would stop showing only posts from a few blogs in early time zones. If it works for you, great.
I have every hope that this plugin will be made obsolete by the default sort order being changed in the WordPress core. I can think of no good reason why comments are sorted by GMT but posts by local time.
For all I know, this plugin works with older versions than 3.0. I’ve only tested it with 3.2.1.

Posts by GMT

Changes the default sort order for posts from post_date to post_date_gmt.

Default Post Sort vs Posts by GMT