As I mentioned in another thread there's tin, and there's also bismuth.
Tin melts at 450*F, you can buy it here:
TIN Ingot form 99.8+%- Pure
Bismuth melts at 520*F, and it can be purchased here:
Pure Bismuth Ingot from Rotometals
There's also antimony, but it melts at 1166*F and may not be feasible for conventional lead melting furnaces. You can buy it here:
Antimony
All of these materials are much more expensive than lead per pound, but by being considerably lighter than lead you will get more jigs per pound... but your jigs will be lighter and you may need to increase the size of them.
I for one will be stocking up on lead, and if lead is outlawed... this outlaw will be fishing with lead!
.. btw, you can buy lead at Rotometals too. They have great service and free shipping if you buy a large enough quantity... I like the "Hardball" mix for my jigs.