$10 buys you a cheap headset with a 1/8" headphone jack to plug into a cordless or cellular telephone. Not an earbud, but an honest-to-Gawd headset with a wire bale to hold it on your head. When you call your insurance company or anywhere else where you're going to be put on hold or sent to Voicemail Hell, these things are worth their weight in diamonds. I've got one at the PD for when I have to call Dispatch for info, too. (That being low-priority, I always find myself being put on hold.)
Being able to type, move around, get things done, and not have to hold my hand to my ear somehow manages to reduce my irritation at being on the phone a LOT.