This site enable you to simultaneously post to Facebook, Twitter, LinkedIn, Buzz, Ping and a couple of others as well.
This service constantly scans the various sites and informs if there is any API and such other problem.
Add to this you can also utilize its scheduling services. Herein you simply have to put date and time on when and which site should your posts be delivered.
Have you tried dlvr.it ? What is your experience with this site. Do share in your feedback. What similar platform do you use?