I use the AMEX Platinum (US) conceirge frequently and the Visa Signature conceirge occasionally. I called Visa to inquire about tickets to the Grammy's, and they said they'd go through a broker. I also asked, on a different call, for information on Coldplay concerts in TX, and they emailed me a list of Coldplay's remaining dates (none in the U.S.) on their current tour. They seem very professional and I have one person I can talk to (assuming he's working at that time) anytime I need assistance.

AMEX can be more hit-or-miss, but they've helped with some obscure things. A friend wanted a birthday cake delivered to a friend in San Diego the next day, and she wasn't willing to spend more that $35. AMEX's usual supplier charges $40 or $45, but told of the $35 cap they spent several hours calling bakeries in San Diego, ultimately finding one that didn't accept AMEX. They called me, provided the info, and we had the cake delivered. I've also used AMEX extensively to get restaurant reservations. They're great. The Pillar House, a restaurant in Massachusetts, was going out of business and told me they had no remaining bookings. AMEX called and got me a reservation even though the Pillar House had never been on their fine dining program. AMEX has also gotten me reservation at Au'jourd Hui in Boston and other top restaurants during Restaurant Week. I most often use them upon arriving at a restaurant to find a long wait. At the Clay Pit in Austin, a restaurant that's not part of AMEX's fine dining program, a call to AMEX turned an hour and a half wait into a 15 minute one. I've had similar results with fine dining restaurants in New York.

-Merrick