PuRam is their marketing term for solid state hard drives. Essentially, it's a collection of flash memory adressable as an ATA device. This means that it looks like a hard drive to your OS, but performs as fast as RAM. They're really
expensive (on the order of $750-1000 per GB) but offer the best performance available at what is the modern PC's most significant bottleneck, the HDD. Check out the solid state disc faq
for more information.
Such drives are available from many places other than go-l, however, and as I'm sure others will be saying in this thread, as a company they're at best way too expensive, at worst a quasi-scam.