Thanks guys, after struggling with various mount/umount parameters/situations and at a last try be for format & reinstall, it fell trough.
I booted up on the Gentoo LiveCD, mounted /dev/hda3 to /mnt/gentoo and was from there (/mnt/gentoo/etc) able to edit/correct fstab and save and everything boot's up beautifully now
This is my second ever Linux install, done one RH9, so there is a lot of "man howdoesthisf*****gcommandwork" going on so sorry for my novice newbie post.
Now i just have to build some KDE on top of this (btw, is it possible to change where emerge downloads it's packages from, some settings file or something)
That second line should have been
/dev/hda2 none swap sw 0 0
And honestly, i donít know what the 's' is for, I'm just following the manual