The Ubuntu/Debian installer includes a built-in guided partitioning recipe, called 'multi', which creates separate /home, /usr, /var, and /tmp partitions. It can be selected by starting the installer with a preseed file. You can see it described in the Karmic install guide:

# You can choose one of the three predefined partitioning recipes:
# - atomic: all files in one partition
# - home:   separate /home partition
# - multi:  separate /home, /usr, /var, and /tmp partitions
d-i partman-auto/choose_recipe select atomic

Is there any way to use guided partitioning with this recipe from the Ubuntu alternate install CD without the need to create a preseed file?