Vincent Brown was let go today by San Diego. He would be an interesting option for the Titans.
Of course the other interesting piece here is that he played for Ken Whisenhunt last year in San Diego. He finished last year with 41 catches for 472 yards and 1 touchdown. While those numbers aren't great, they are better than anything Michael Preston or Derek Hagan have ever put up.
The biggest problem with Brown would have to be that he hasn't been able to stay on the field. He has only played in 30 games in his 3 years in the league. I'd still take a shot at him.