Raiders have reached out to David Garrard. It doesn't mean they will sign him, but it does confirm there is some level of interest.
Garrard has been waiting for a chance to go to a team and start and he could very well get that chance with the Raiders. The team is also said to be interested in Carson Palmer, but it's highly unlikely the Bengals will move Palmer, esp. to the Raiders who are without several of their 2012 draft picks. Garrard could be worth a pickup if you're hurting at the position but it's best to wait for something official.