How can I change OSX's spinning beachball pointer animation?
If you go to /System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/HIServices.framework/Versions/A/Resources/cursors you'll might find something useful :

MBP-Thomas in ~
○ → cd /System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/HIServices.framework/Versions/A/Resources/cursors

 MBP-Thomas in /System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/HIServices.framework/Versions/A/Resources/cursors
○ → ll
total 0
drwxr-xr-x  41 root  wheel   1,4K 13 sep  2013 .
drwxr-xr-x  39 root  wheel   1,3K 26 mai 23:30 ..
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 busybutclickable
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 cell
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 closedhand
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 contextualmenu
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 copy
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 countingdownhand
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 countingupandownhand
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 countinguphand
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 cross
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 help
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 ibeamvertical
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 makealias
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 move
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 notallowed
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 openhand
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 pointinghand
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 poof
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizedown
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizeeast
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizeeastwest
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizeleft
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizeleftright
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizenorth
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizenortheast
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizenortheastsouthwest
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizenorthsouth
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizenorthwest
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizenorthwestsoutheast
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizeright
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizesouth
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizesoutheast
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizesouthwest
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizeup
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizeupdown
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 resizewest
drwxr-xr-x   5 root  wheel   170B  9 déc  2013 screenshotselection
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 screenshotwindow
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 zoomin
drwxr-xr-x   4 root  wheel   136B  9 déc  2013 zoomout


Which are a lot of folder containing cursor pictures