Here is a nice article on how Kim Cascone switched from Mac OS X to Ubuntu for setting up a Music Workstation using very inexpensive hardware costing a tenth of what a similar solution from Apple would cost.
“The solution to my financial constraint became clear, and I bought a refurbished Dell Studio 15, installed Ubuntu on it, and set it up for sound production and business administration. The total cost was around $600 for the laptop plus a donation to a software developer — a far cry from the $3000.00 price tag and weeks of my time it would have cost me to stay locked-in to Apple. After a couple of months of solid use, I have had no problems with my laptop or Ubuntu. Both have performed flawlessly, remaining stable and reliable.”