I have a La Cie external drive conected via firewire and when I plug the cable in in mounts on my desktop, but I hate the noise of the fan so after I am done with it I eject it. Now it's still pluged in,, but it just doesn't show. How do I get it to show up again without unpluging it and pluging it back in.
Well, you can go to APPLICATIONS > UTILITIES > DISK UTILITY and click on the drive and hit Apple-M, I think, to mount it.
All in all I think it's easier to just un-plug the thing unless it's way behind a desk or something.
What you should do instead is go to the System Preferences > ENERGY SAVER and check "Put Hard Disks to Sleep when Possible"
If you do that after you're done using your drive it should go into a kind of sleep-mode after a few minutes. Whenver you click on it again it will come back to life. This is all done without ever un-mounting it.