a a Reasonably new in the field of RAM Disk's, but this product is the best of the bunch. Great simple UI, active development, responsive developer. Works on XP and above, both 32-bit and 64-bit.
This can be used in conjunction with something like Sandboxie to allow you to browse without any traces being left on the hard disk, since everything is stored in RAM, which can also be wiped when the disk is unmounted (if required). Completely isolated browsing.