Where's your checkbook? Do you have it on you right now? Chances are pretty good these days that you don't. Americans are writing fewer checks than ever, heavily preferring card transactions in person and online and digital payment options when available. As a result, more and more property management companies now offer online payment options for rent, applications, and other charges. But in an interesting wrinkle, many renters are still delivering a rent check to the leasing office like clockwork, on the first of every month. Where's the disconnect?