Klausner Technologies Inc. has filed a $360 million lawsuit against AT&T and Apple for allegedly violating two of Klausner's voicemail patents. Klausner has brought other people to task on the two patents in question before -- once for AOL, and once for Vonage. Klausner has also sued Apple before for patents pertaining to the long-gone Apple Newton; Apple ended up licensing the patents back then.
Everyone was talking about Burst's patents too and and the hundred bajillion dollar lawsuits there, but my guess is that Apple will be fighting this one tooth and nail -- it seems that Apple would rather pay their lawyers to get patent-holding companies' patents tossed than pay for patents. Klausner Tech is apparently website-less, leading me to believe that it's a patent-holdings