I have just installed Ubuntu 7.04 (Feisty Fawn) on my Mac Pro and MacBook pro. Both installs use 2.9 Gb without any data or additional apps. BTW I just wanted to dip my toes in the Linux waters and initially tried to download the ready made images linked elsewhere on this site. A royal pain, very slow torrents and after three days I got one complete, but it was the previous version (6.10) and the upgrade didn't work. Downloading the 7.04 ISO and doing a fresh install was very easy and quick.
Nevertheless providing here http://ptn.parallels.com/en/ptn/desc/?va_id=228 preinstalled Ubuntu takes just 727 Mb disk space. The size of installing Ubuntu depends of install configuration (num of packages that would be installed).
727 Mb disk space is consumed by PVA package. The real disk space requirements see at 'Host OS Requirements': at least 2 Gb for the Ubuntu Desktop PVA
