[From Eric Mann] Brighthand comes up with a good piece of information, Treo 680s Can Use SDHC Cards, Despite What Palm's Support Documents Say. "Shortly after the release of the Treo 680, there was some buzz about a possible -- yet not documented -- support for Secure Digital memory cards larger than 2 GB (commonly referred to as Secure Digital High Capacity or SDHC). Many users reported on this after a few people found out that their 4 GB SDHC cards worked in the Treo 680. The issue become an even hotter topic after the quiet release of an 8 GB SDHC memory card by Transcend and others, and an accompanying low price in the area of $60. I took a chance on a Transend 8GB SDHC card purchased at NewEgg and can report that not only does the SDHC card work, but it works very well."
Brighthand