Sare marjon ki ek dawa... SGD or Super Grub Disk . Get ISO image from this link :
*adrian15.raulete.net/grub/tiki-download_file.php?fileId=95
or Floppy from
*freshmeat.net/redir/supergrub/66544/url_bz2/tiki-list_file_gallery.php
There is one for generic USB device too
*freshmeat.net/redir/supergrub/62945/url_tgz/tiki-download_file.php
Fixing Grub blues doesnt get any simpler than this. F&#k your MBR, GRUB to your heart's content and then boot up with this CD/ Floppy. Dont have to bother about any CLI. Complete menu driven wizard like interface can automaticaly recover your GRUB, LILO and even Windows MBR. You can even load an installed OS directly without the rebooting. I have used it a number of times recently while experimenting with Xandros, FC5, Suse and Ubuntu.
Have Fun..