I've been testing out some tablature software and was pretty happy with TuxGuitar. I downloaded a ".tef" file (for a mandolin song), and was able to import and hear it with no problems. TuxGuitar also has an optional neck view, to step through the finger positions.
On Ubuntu, there was an older version in the repository, so I downloaded the newest 1.2 version directly from the website:
There's also a java version online as well, but I haven't tested it out.