Magnetic Silly Putty - Thinking Putty Answered
A friend of my friend Rhett just launched Thinking Putty, which is ferromagnetic silly putty. You might recognize the site, Crazy Aaron's Puttyworld, as they had some ads on Instructables last Christmas season (for full disclosure, at the time I didn't realize I was only one degree of separation from the advertiser, and now I'm posting this because I think it's cool, not because of an advertising relationship). According to Rhett, this new grey stuff feels exactly the same as regular silly putty, and it is pretty strongly ferromagnetic, as you can see from the videos. Aaron apparently has a ridiculous amount of putty related chemicals in his basement, and it took him a few years to figure this out.