As a general rule the spinny wheel should by tied to a particular application. Are you noticing this somewhere specific, or does it appear to be system wide? I

As a general rule the spinny wheel should by tied to a particular application. Are you noticing this somewhere specific, or does it appear to be system wide? I ask because if it appears to be system wide it could be indicative of a hardware problem or a misbehaving 3rd party driver. Healthy stock Macs running stock software don't go tend to go spinny system wide (excepting the disappearing network filesystem mentioned elsewhere in this thread, although even that is less of an issue in 10.6), at least in my considerable experience. Your mileage may vary with 3rd party software and drivers (although in my experience, most of those play quite well). I've had similar experiences with Windows: if you stick to software supplied by Microsoft, the system tends to be fairly stable. Perhaps I'm just lucky.