Hello Pedro,
with CEF base multilayer switching you can:
by default have a flow based load-balancing that uses
source ip EXOR dest ip EXOR hash
if you have a good number of concurrent flows >=100 and traffic volume on each flow is comparable you can get a good balancing
in the command reference shows a command for changing the load-balancing algorithm:
ip cef load-sharing algorithm
To select a Cisco Express Forwarding load-balancing algorithm, use the ip cef load-sharing algorithm command in global configuration mode. To return to the default universal load-balancing algorithm, use the no form of this command.
ip cef load-sharing algorithm {original | tunnel [id] | universal [id] | include-ports {source [id] | [destination] [id] | source [id] destination [id]}}
http://www.cisco.com/en/US/docs/ios/ipswitch/command/reference/isw_i1.html#wp1011833
the command is available in 12.2SX and from 12.2(33)SRA
Hope to help
Giuseppe