This is only possible on the ingress of the interface since the 2950 (and only the EI versions) supports only ingress policers.
ip access-list standard all-ip
permit ip any any
!
class-map match-all all-ip
match access-group name all-ip
!
policy-map limit-1mbps
class all-ip
police 1000000 8192 exceed-action drop
!
interface FastEthernet0/1
service-policy input limit-1mbps
!
The catalyst 3550 supports ingress & egress policers. The newer 2960, 2970, 3560 & 3750 only support ingress policers (progress eh?).
HTH
Andy