First let me thank you for the pointer to MagicPrefs. It appears to do everything Apple has promised for the Magic Mouse "in a future update" and at least for now it appears to have solved my jumpy Magic Mouse in Java applications. Dialing down the sensitivity appears to have been the key. My wife took one look at MagicPrefs and said, "I want that on my MacMini - NOW!" After 50+ years of marriage I know what "NOW" means. Now - we both have MagicPrefs.
As far as Magic Mouse batteries go, I find regular Duracel AA batteries last anywhere from four to six weeks. My wife typically gets a week or two or more battery life than I do but I have a friend who often gets a week or two less than I do. The only difference I can account for is how much each of use uses our Magic Mouse which is a function of our personal work styles. The batteries in the wireless keyboard seem to last at least twice as long - go figure.
As a dedicated gadget freak, I got Apple's new "green" battery charger last week which comes with six NiMH AAs and I have two in the Magic Mouse now. Of course I haven't had them long enough to get any idea of how long they will last between charges. However I noticed when I put in a freshly charged set of the NiMHs they only indicate around 68% charge while the Duracel alkalines typically will show very close to 100%. I surmise this is because of the way the battery level is measured, and NiMH delivers slightly less voltage than alkaline batteries do. As of yet I have no idea what this means for time between charges but my suspicion is I will have to be recharging more often than I have been replacing.
