I am not sure, but...
If I remember correctly, the latest version of Ubuntu includes HFS+ support (the file system on current-day Macs). If you boot a LiveCD on your Macbook (insert the cd/dvd at boot and hold C) you may gain file access if the hard drive will physically respond. From there you could probably get files onto a USB drive.
Alternatively, you could open the laptop up (very easy) to get the hard drive out and replace it. From there, insert your Mac OS X disc and hold C to reinstall. With the old drive, you could try chaining it with your PC and trying a solution like boopme suggested. If the drive is clicking, though, it may (but not necessarily) be pretty dead. An old trick is to put the hard drive in the freezer and then connect it before it warms up, that trick has mixed results though.
I had success with a Mac's clicking hard drive at the shop one time when I connected it to the newly-install Mac with a SATA->IDE connector on a IDE->USB adapter. It took FOREVER for the hard drive to transfer data over, but eventually I got everything--it took about 3 days though.