Open up some space with Parted

In the past all my partioning needs have been easily met. Either I re-did the whole drive or initially partioned the drive through partion magic and windows. I currently have Debian testing installed on a 30GB drive as ext3 and I want to open up about 5-10GB for another distro. I have Parted installed but am not sure how to start. I would essentially like to set up the free space as unpartioned. Is this possible or do I have to set it up as ext3?

IF you want to 'open up' space for another distro,
AND the whole disk is partitioned with not free area,
THEN you need a way to shrink filesystems (I don't know a tool for doing this with ext3) to create a free area.

If you do have a free area on the disk, just point the install to it and it will partition and format appropriately.