Have you ever had the need to perform some I/O intensive operation on a relative small set of files? I do, usually when I need to compile some application.
In order to speed up this operation I've recurred to the so called "RAM Disks", applications that takes part of your computer's main memory and pretends that it is an actual disk. As you can imagine read/write/etc (I/O) operations against this virtual disk are much faster than operations against your actual hard disks (be it a traditional magnetic HD or a shine new SSD).
In the past 3 years I've used at least 3 different solutions and was happy with none. My main complain is that most of them were not capable (or it was really clumsy/hard to accomplish) of creating RAM disks dynamically, i.e, one is required to create it at OS start up time. Since my needs are dynamic (I may need more disk space at some points in time during the day) it is really hard to come up with a disk size that work for me: choose a to big disk and I am wasting precious RAM space; create a disk that's to small and I may find myself facing "out of disk space" errors (then cleaning up some junk and restarting my build tasks).
Fortunately some time ago I stumbled upon a RAM disk implementation that allows me to mount and unmount disks dynamically! Since then my work flow has been much more smooth ;) The not so good side is that it is not very easy for the "not computer savvy" user.
Bottom line is: if you need a stable and flexible (but maybe not so easy to start with) RAM disk solution you can't go wrong with this one.