For many Americans, cash is not king. More than three-quarters of respondents to a recent U.S. Bank survey said they never carry more than $50 in currency with them. Nearly one-quarter said they keep $10 or less. And, when given a choice between paying someone with cash or a peer-to-peer (P2P) payment app, 47% said... Caren Weiner Campbell is a writer at NerdWallet.