Changing the order of posts is something very convenient within a WordPress blog, and thankfully we’ve always had a few plugins that did the job very well, even providing us with an Ajax interface which made this task really easy and intuitive.
My favourite one is the excellent Simple Page Ordering plugin.
Order your pages, hierarchical custom post types, or custom post types with “page-attributes” with simple drag and drop right from the built in page list.
Simply drag and drop the page into the desired position. It’s that simple. No new admin menus pages, no clunky, bolted on user interfaces. Just drag and drop on the page or post-type screen.
The plug-in is “capabilities aware” – only users with the ability to edit others’ pages (editors and administrators) will be able to reorder content.
Integrated help is included: just click the “help” tab at the top right of the screen.
The only problem with Simple Page Ordering is that it only reorders pages and hierarchical custom post types.
If you need support for Posts or non-hierarchical custom post types, I suggest the excellent Intuitive Custom Post Order which I’ve used successfully to re-order products on my online plugin shop at WPRSSAggregator.com. Unfortunately if you’re using this plugin it will prevent SearchWP from working properly, so keep it in mind if you plan to run both those plugins on your site.