It's rare when you find a company that encourages overclocking. Not so rare as it was 10 years ago, but still not something you are accustomed to. Even rarer is a company that will go so far as to letting you reprogram the firmware on their hardware to such an intricate level as the SPD on memory. OCZ, reaching out to their enthusiast customer base, is definitely going out on a limb here with their latest offering. "SPD-Z" as it is called will allow someone to alter SPD settings on OCZ memory modules, allowing someone to tweak memory in a level never before possible.
It isn't fully open-ended, however, requiring that you download an SPD file from the OCZ forums, which the SPD tool can then flash the memory with. The reasonings are sound. Particularly with the high-end modules and chipsets that supported non-JEDEC certified speeds, people want and need greater flexibility over how to configure their memory. Further, many memory modules will require different timings based on what chipset and what CPU is being used at the time. For people that are really in to overclocking or tweaking, this is definitely an interesting tool to look at.
The SPD-Z utility only works with OCZ memory modules, and is a Windows-only program. The program is considered to be in beta, so beware if you are planning on tinkering. They mention it should work with any motherboard, regardless of the existing chipset.