Corsair have just released some performance oriented 2GB SODIMM modules for notebooks, these being DDR2-667 parts as a member of their "ValueSelect" series. Two or even one of these modules whacked into your lappy make for some very nice headroom in conjunction with Windows Vista!
More details here peeps.
FREMONT, CA (January 30, 2007) - Corsair®, a worldwide leader in high performance computer products, today unveiled production-ready 2GB DDR2-667 (PC5300) ValueSelectTM SODIMMs. Designed for current generation notebooks and mini-PCs, the new high density SODIMMs allow users to maximize memory bandwidth and minimize performance bottleneck to deliver superior user experience. The Corsair ValueSelect SODIMMs are optimized for Microsoft® Windows® VistaTM client operating system.