IDK where you guys are looking, but there's no shortage of FW Cardbus adapters... Almost everybody that makes a PCI card adapter makes one or more Cardbus ones too; Belkin, Keyspan, VST (SmartDisk), Western Digital, etc, and then there's all the no-names.

[Edit]Keyspan's, Belkin's, and Mac/PCAlly's are dongle-ed, among others[/Edit]