Lead free solder is not the "organic" type.
Radio Shack and a lot of "normal" electronic stores don't carry anything
but rosin core. Planning a bit ahead and ordering from Mouser is really
the way to go; saves running around in the car at the last minute.
Some of the best prices for 331 and 245 are from Future-Active.
Regards,
-----------------------------
John Blacet
Blacet Research
http://www.blacet.com