We went to the Bristol Lounge at Four Seasons for "Power Tea" on Saturday, before going to a movie at Boston Common ("Mystic River" is good, but disturbing). As Jane posted below, it's a decadent, if very expensive treat. Not enough food for dinner, so we order a burger and club sandwich as well, which were nothing out of the ordinary (except price-wise). But there's nothing like relaxing for a couple hours on comfy, over-stuffed sofas, toasting old Scotch and pretending to be nouveau riche.
Power Tea is not mentioned on their web site, but apparently it runs from 3-7PM (at least on Saturday) and jazz piano started ~6:30PM. They also set up a spectacular looking desert buffet later.
$170 + tax for three ($95 for just Power Tea).