Is per-packet appropriate for your application? Unless the number of source-destination pairs is very low, you're better off with per-destination. See the URL below for more details...
Configuring Cisco Express Forwarding:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/switch_c/xcprt2/xccefc.htm
Use the command 'show cef interface' to confirm load-sharing status...
Router>show cef interface FastEthernet 0/0
FastEthernet0/0 is up (if_number 3)
Internet address is 172.19.177.20/24
ICMP redirects are always sent
Per-packet load-sharing is disabled <---