Linux On Macs
On a typical PC, installing Linux is as easy as putting a CD in the drive and rebooting. But, a Mac is far from your typical PC, and if you insist on running Linux natively, you might be in for a bit more work. Apple is not exactly forthcoming with information, especially with firmware, which makes the job of the distributions that want to support Macs difficult. In addition, Macs from different release years can contain very different hardware, one MacBook is not necessarily the same as another. That being said, once the drivers are installed and the system is configured, Linux on Macs can be a very nice environment, if you are up for a bit of fiddling.
This recent Reddit thread reminded me of the many times I've run Linux on my Mac. I have a 2009 MacBook Pro that I've gone back and forth on using Ubuntu, FreeBSD, and OS X. The first thing you will need to know when installing Linux on a MacBook is that the wireless will most likely not work out of the box. I have always needed to hook up to a wired Internet connection after installing to download the non-free driver needed for my particular chipset. After running the install and patching to the latest level though, everything runs fine. Wireless, the built-in "Facetime" camera, bluetooth, and the speakers all work without problems after the first update.
That's not to say that Linux is not without its oddities on the Mac. It is recommended that you keep a small partition for OS X available and dual boot the computer to apply the occasional firmware update released by Apple. I've always found the trackpad to be a bit of an annoyance, it is either too sensitive or too slow, and requires some tweaking.
If you are ready to take the plunge, choosing a well supported distro will make things much easier. Ubuntu in particular seems to have good support for Macs, but they are not the only ones:
It is possible that some devices will not work, especially if you have a newer thunderbolt equipped Mac. It is also possible that you may experience a notable decline in battery life when using Linux over OS X. However, most of the responses I've seen, as well as my own experiences, have been very positive. If you have experience running Linux on Apple hardware, the Reddit thread would love to hear from you, and I'd love to hear from you in the comments.