Very good web 2.0 tool which can cross post your messages to large number of different social websites is Ping.fm. Ping.fm is a simple service that makes updating your social networks a snap. With just one click post to Twitter, Facebook, MySpace and many others. There are different micro-blogging, blogging, bookmarking and social network platforms and developer keeps adding services.
Cross posting may be useful if the message is of interest to a larger audience. However, cross posting to groups where that message is irrelevant could be considered spamming. The solution is simple. With Ping.fm you can decide which social services you wish to post the message to (see image bellow). You can update separately:
- micro-blogging (Twitter, Tumblr, Pownce…),
- blogging (WordPress.com, Blogger),
- status ( social networks like MySpace, Facebook…),
- singular social or blog network,
- or make your unique trigger and determine in advance which networks to update with each particular trigger.
To set your custom triggers go to Ping-triggers (you have to be logged in to reach this page). This way you can set custom number of networks for one trigger and make each message fit to networks you want to cross post.
I advice you to check other Web 2.0 tools.