A recent announcement from Transcend introduces their latest 533 and 667MHz unbuffered DDR2 modules which measure just 1.2 inches in height.
Grab the official PR here for further details folks.
Transcend Information, Inc. is very proud to announce the release of the world's highest capacity 2GB DDR2 533/667 Non-ECC Unbuffered DIMM memory modules (P/N: TS256MLQ64V5U/6U). Transcend's DDR2 533/667 Non-ECC Unbuffered DIMMs have a huge 2GB memory capacity, measure only 1.2 inches in height and are specially designed and engineered for speed, reliability and extreme performance. All of these attributes make these modules perfect for use in high performance desktop computers, which contain chipsets such as, Intel's 915GV/945G/955X, AMD's AM2, or Apple's iMac G5 17" 1.9GHz and 20" 2.1GHz chipset solutions.