announced the availability of 2GB PC2-6400 (800MHz) DDR2 SO-DIMM modules for high-end laptops. These modules are available as single modules or 4GB kits.
The rated latency is 5-5-5-15 and operates at 1.8V. A pair of these modules should be ideal for running 64-bit Windows Vista on a notebook.
No price was listed, but we'd expect these modules to be quite expensive. OCZ also offer a 1GB module that is also available as a 2GB kit.
You can find out more here