If you are running OS X Lion, I recommend updating to the just-released 10.7.3 update via the downloadable Combo Update, which is the way I always update my systems. (Given the problems people have been reporting with the smaller "delta" 10.7.3 update released through the OS X Software Update mechanism, the combo updater should be safer.)
If you are not yet running on Lion, but want to upgrade (check system requirements) and are interested in upgrading RAM (I recommend upgrading to your Mac's maximum, typically 8GB) or hard drives (I have 500GB and 750GB for laptops and 1/2/3TB drives for desktops), drop me a line!
