I use
Hootsuite to manage my twitter activity and recently they added the ability to be able to send updates to Facebook (including Fan Pages) and LinkedIn, plus of course the management of mulitple twitter accounts.
So I can cross post to the platform of my choice using Hootsuite, might be something to look at.
The RSS feed could also be an option, but I like using Hootsuite because I can then pick and choose which updates I'm sending to which account or page.