Linux with no primary partitions left

I got a new company PC, an Acer Aspire 5372ZG, nothing to say about it, just yet another consumer notebook with a 15.6" 16/9 gloss display, very big and quite heavy, nice keyboard if you don't mind having the home and end key on the keypad only.

The problem is, the 320GB HD is partitioned into three partitions, two of them are hidden. All are primary partitions. No primary partition left to install linux. So I did my homework and discovered that unlike the lilo of old, Grub is able to boot quite nicely from any filesystem it is compiled to support.