The aptly-named Posty is a nifty little tool that addresses a very specific concern: multiple posting in different microblogging platforms. A tool like this makes sense if one takes into account the ever-widening number of microblogging services on offer, and the fact that the percentage of users that employ more than one is considerable.
What Posty allows you to do is write a message and post it in as many services as you wish at the same time. Some of the supported networks include Twitter, Pownce, Friendfeed and Identi.ca.
A link for downloading the latest version of Posty as a ZIP file is included, and a screencast that showcases how to best use Posty and get acquainted with it is featured as well.
When all is said and done, this is a worthy addition to the family of tools and applications that aim to expand the power of microblogging platforms.