I want to make my own blog in which ,
I want to provide facility of posting a single post to multiple sites .
I can build my own database and interface for my blog but how can I add facility of multiple posting in my blog I know it is possible with web services but I dnt know how and using php.
Thanx in advance

The simplest way is to use an existing service like Wordpress or Blogger.com. You can optionally download one of these applications and put it on your own site. If you are implying that you want to build your own blogging system from scratch, then based on the question that you're asking, I'm guessing that you aren't ready to do that (if you really want to use it for blogging versus doing it as a learning exercise).

With respect to posting on multiple sites have a look at this.

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