My iBook has the spinnies. That is I now see the spinning colourwheel way too often. I'm not sure what the heck is going on.
Symptoms are that every so often it just locks up - one app starts spinning and then another and then another... and all of a sudden it'll free up and execute all the GUI events I'd tried to do while it was frozen. And now whenever I start certain applications (e.g. textedit) they start fine, but spinnie for a long time before I can type anything in.
Very strange, and a reboot (???!!) doesn't fix it. I guess an OS re-install is due