I have a dual-boot Mac that currently has three partitions... OSX, Win7-64 and Data. I have shrunk the data partition to make some free space. I've then installed rEFIt as the new boot menu. My plan is to install Ubuntu 11.10 or 12.4 in the newly-freed 20 GB of space via a single partition, but every single install documentation I've seen says Linux needs three partitions... system, user and swap.
Now I know Ubuntu can be installed on a single partition because I'm using a VM with a single disk image and it runs fine. However someone else set that up and I don't know how.
Also, this is a very minor-use install (we just have two utilities that have to run on Linux) and this system has a SSD, so I'm not really worried about speed here. I just want a single partition instead of three.
So how can you set that up?