You could try pluggin in an external keyboard, maybe that will override the internal keyboard and let you at least install stuff then you could try to fix the problem once the distro is installed.
Or you could try a different distro and see if it has the same problem. Try Mandrake, Suse, or maybe Knoppix.
Finally check out
http://www.linux-on-laptops.com/ and see if you can find your particular laptop that someone else has installed Linux on.