Xavier Media

This plugin will do a backup of your WordPress database and, or your files in wp-content/uploads and saves 
it somewhere safe. You can have the backup saved in your <a href="http://db.tt/9Jo39Xy" rel="nofollow ugc">Dropbox account</a>, a FTP account of your choise, your 
account with <a href="http://www.securepaynet.net/email/online-file-storage.aspx?ci=1796&prog_id=xaviermedia&isc=xmbackup" rel="nofollow ugc">Online File Folder</a>, or have the backup emailed to you (not recommended for large files). You can 
select to have the backups named the same every day or to have a date added to each file name.
This plugin requires PHP, cURL, PHP compiled with ZIP support, and Oauth (for Dropbox).
** NO WARRANTY SUPPLIED! **
** Make sure you test your Backups! **

XM-Backup

Does a backup of your Wordpress database and, or your files in wp-content/uploads and saves it in a safe location.

PaoloBe

Post via Dropbox is a easy way to update your blog using Dropbox, the famous cloud sharing service. It permits to add or edit your posts with text files uploaded via Dropbox.
Once you linked your Dropbox Account, you can upload text files into your Dropbox folder for updating your blog. It supports also Markdown syntax. 
Everything happens automatically and without further actions on your part.
Please read the readme file or Help & Faq section for further informations and instructions.
Post via Dropbox requires WordPress 3.0 (and above), PHP 5.3.0 (and above) and a Dropbox account.

Post via Dropbox

Post via Dropbox allows you to post or edit your blog with text files uploaded via Dropbox. It just works seamlessly without any effort.

XM-Backup vs Post via Dropbox