Since the 6500 does all L3 switching in hardware (MLS), it cannot do per-packet load sharing like routers can using CEF.
However, it can do better than per-destination load sharing. You can configure MLS to load-share per-flow, or per source/destination IP/Port.
Here is a doc on how to confige that in cat-os:
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_6_3/cmd_ref/set_m_pi.htm#wp1051943