Today's fun project: Installing the latest macOS on an early 2008 17" MacBook Pro!
Officially the MBP topped out at OS X El Capitan (2 OS's ago, not counting the upcoming macOS Mojave). With a simple software hack, you can trick the High Sierra installer to install and run on this and other ancient hardware.
I used the macOS High Sierra Patcher from
http://dosdude1.com/highsierra/ to make a bootable USB drive using a 2013 MacBook Air (though I guess I could have done it with the old MBP as well).
After backing up the existing installation "just in case", less than an hour later I had a "modern spec" 2008 computer! Which, BTW, was given to me for free. I had already replaced the old spinning hard drive with an (also) older 120 gig solid state drive; now a larger SSD might be justified depending on what I will use this for (it currently has 100 gigs free, even after installing some useful apps).
The OS hack (as expected) broke the wireless, but a newer wifi card can be installed. And the current 2/2 GB RAM setup can be upgraded to 4/2.
But even in its current state, the computer feels surprisingly fast.