newegg offers the Corsair 8GB PC3-8500 DDR3-1066 204-Pin Dual Channel Notebook Memory Kit with two 4GB SO-DIMMs, model no. CMSA8GX3M2A1066C7, for $39.99. This $10 mail-in rebate cuts it to $29.99. With free shipping, that's the lowest total price we could find by $9, although we saw it for $5 less last month. It features 7-7-7-20 timings. Rebate expires January 31.

Although it's designed for use with the MacBook Pro, MacBook, and other Apple laptops, it should work in most laptops that accept this kind of RAM.