What is this suit about? It looks like it relates to the touch-sensitive click wheel in the iPod.
What patent is it about? 5,730,165 
What’s in the complaint? There are two complaints from Quantum. The originally filed Complaint from December 21, 2005 and an Amended Complaint from May 11, 2006. You can also review Apple’s Answer to the complaint and Cypress Semiconductor’s Answer (they were added as a party in the Amended Complaint).
Um. OK. But what’s it really about? Quantum is claiming that Apple, FingerWorks (now believed to be owned by Apple), and Cypress all infringe the patent. This patent relates to capacitive field sensors. Quantum alleges that the technology covered by this patent (specifically claims 42-62) are used in Apple’s products. Quantum does not mention any specific products, but an educated guess could be made that they’re referring to the iPod click wheel.