You know, I got to thinking about this and realized I have connected my phone to system and have been able to mount the card. I'm running Ubuntu 12.04 on my desktop. It's not a dual boot, just straight Linux. I connected my phone the other day and selected the option on the phone's USB connection menu to mount the card. From there, I was able to go into the that drive and view all folders on my card. It won't autorun like in Windows and open up a window to that drive, but it will work.
What version of Ubuntu are you running?