I would suggest that the largest percentage of flapping prefixes in the global routing system belong to prefixes longer than /19.
Hence the convention to damp differently for different lengths. See one of the foils in http://www.psg.com/~randy/970210.nanog/, which suggests that we over here start following the European lead on this.
Also, the dampening defaults:
bgp dampening <halflife-time> <reuse> <suppress> <maximum-suppress-time>
<halflife-time> default is 15 minutes <reuse-value> default is 750 <suppress-value> default is 2000 (I thought it was 1000, but docs indicate otherwise) <max-suppress-time> default 4 times halflife-time
Wellllll. To be tactless ..... If the ops are heading toward the above-described convention, would it not be cool if the router vendors made it the default? randy