Does it make the noise in neutral with the clutch out? Does the noise go away when you push the clutch in? If so it's more than likely your release/throw out bearing. No problems, you can drive it until the noise drives you nuts or the clutch dies.

If it makes noise in gear, with the clutch in, under load and it gets louder with higher revs, then you could have a pilot bearing problem. This usually happens to people who rest their hand on the shifter while driving. Which places extra load on the bearing.