now here's some stupidity for you: i just installed solaris 9 and i changed the login shell for root in the /etc/passwd file. i guess bash isn't located in /bin/bash, b/c now i'm getting a 'invalid shell' when i try to login. i have no other user accounts, and i have no clue how i can edit /etc/passwd w/o being logged in. there is some interactive boot menu, but i couldn't get to the filesystem from there it seemed. any ideas or do i have to reinstall?

I don't know what filesystem type Solaris uses, but you could Knoppix, or some other LiveCD, to boot the system, mount the partition, and edit the file.

Solaris use ufs and knoppix recognize it (ufstype=sunx86)

Two comments:

This works only if you are running Solaris x86.
With Sparc H/W, the easiest way is to boot on the solaris installation 1 disk, then, when under X11, open a terminal window, mount your slice on /mnt, fix the /etc/passwd file and reboot.

Even with x86, ufs R/W support is said to be experimental, so trying to change your passwd file can be risky.
If you have valuable data on your disk, either backup it under linux before doing any write, or just do the same as with sparc h/w.

thanks jiliagre i booted from install and got a prompt, all went fine.