Of course this one requires you to be host.
Walking Speed Address: 0x004A6CE7
Original Code: mov [ebp+5C],000000BE
Modify 0BE to desired value in HEX. Exemple -> 650 = 28A so it should be like this -> mov [ebp+5C],0000028A
I dont know if it affects all players...
Original Walking Speed Value: 190 -> BE (mov [ebp+5C],000000BE)
Walking Speed while Spectating: 400 -> 190 (Another address writes it)
Have Fun! Maybe with this we could find a way for public matches. USE AT OWN RISK!
*EDIT*
It Does Affect all players