Most of the points here are good, but the "Archive and Install" and "Reinstall" suggestions are *almost never* required in Mac OS X, and highlighting them as troubleshooting steps for performance is likely wasting a lot of people's time.

The whole "wipe and reinstall" is necessary wisdom from Windows troubleshooting that is absolutely erroneously applied to Mac OS X, and it will rarely if ever will make any difference on a Mac. Archive and Install will only make a difference if you've somehow hosed up the internals of Mac OS X, which is not something that will normally happen absent some other hardware failure.

Other important points are missed. Performance issues due to hard drive issues can often be detected by opening the Console, selecting the "All Messages" log and then filtering for "i/o error". Any drive throwing I/O errors into the log should be immediately cloned (if possible) to a new drive using the free utility Carbon Copy Cloner (http://www.bombich.com/) and then replaced with the new drive.

SMART errors will sometimes indicate a failing drive, but the absence of a SMART error doesn't necessarily indicate a healthy drive (there are often false negatives with SMART). You can check the SMART status of a drive in Drive Utility in /Applications/Utilities. Click on the disk media (above the hard disk name) and then look for "SMART Status" at the bottom: if the status is anything but "Verified", clone and replace the drive immediately as mentioned above.

A great free utility for ongoing monitoring of hard drive health is CoreCode's SMARTReporter (http://www.corecode.at/smartreporter/), which constantly monitors all of your hard drives for SMART errors as well as your logs for I/O errors, reporting either with your choice of a popup, an email, or by running another application. It will also check any software RAID1 arrays that you may have set up in your system, making it a truly universal disk health utility.

A more comprehensive SMART utility that is great for proactively testing a drive is Volitans Software's SMART Utility (http://www.volitans-software.com). This application's Long Test can be run live on your hard disk in the background and will detect any bad sectors on the disk. More than a few, or an increasing number, indicates that the drive should be cloned and replaced.

One other rare but possible performance issue to check is antivirus software. As more Mac users being to use antivirus software (either just to be as safe as possible or to not pass on Windows malware that they may come across), it's possible for the "Live Scanning" features of these utilities to take a big chunk out of performance. If you have antivirus such as Sophos installed and something is taking a long time that should generally be quick, try temporarily turning off the live scanning capabilities and see if it improves performance.

If things are running a little too slowly and you're running a 5400RPM hard drive (you can check in System Profiler and Google your drive's model number to determine the RPMs), an easy and relatively inexpensive way to increase performance as well as give yourself a space upgrade is to replace your drive with a new, fast one. Any 7200RPM drive will give a pretty significant performance boost over a 5400RPM drive, especially for FileVaulted laptops and others that do a lot of disk I/O. A great source for drives along with Mac support expertise is Other World Computing (http://macsales.com/). To replace your drive, hook up the new drive to your Mac (there are various ways, including my favorite, the NewerTech Voyager, also available from OWC), clone to the new drive using Carbon Copy Cloner, then just replace the old drive with the new one and you're in business.