There's a certain school of thought out there that believes that you can never have enough RAM, but as much its students want to cram as much of the stuff into their systems as possible there are limitations. A company called SMART Modular Technologies is aiming to eliminate one of those, the amount of memory chips that can actually be fit onto a single stick.
The premise is simple: the limitation on the capacity of normal DIMMs is the number of individual memory chips that can be addressed at any one time. SMARTs solution is to place a bridge chipset, from MetaRAM, between pairs of RAM chips making them appear as one larger capacity chip to the systems memory controller.
Not only does this double the current limit on a single DIMMs capacity from 4GB to 8GB, but it also offers power savings by reducing the number of RAM sticks needed to reach the same capacity. SMART suggests about a 20% reduction by going from four 4GB to two 8GB sticks which over a large number of servers could prove a decent reduction in running costs. Especially if you're running a real server with, say, 128GB of RAM - and who wouldn't want to do that?
Currently the modules are only available for servers and run at PC2-4200 speeds (that's DDR2 533MHz for those not fluent in JEDEC designations). Pricing information is said to be available by contacting your local SMART distributor - code for "if you need to ask you can't afford it" if ever I heard it.