TheLilCrocheter: It's pretty much the coolest swap ever.
First you say "I claim package B, gigantic doily! I have 4 claims left!"
And then I say "Nu-uh sistah! I totally claim Package B! Mine all mine! I have 4 claims left!"
And then you're all like "I don't think so, summerthyme! I gotta have me that doily! I claim package B, and I have 3 claims left!"
And them I'm all like "Oh no you didn't! I claim package B, and I have 3 claims left too so there!"
And then you punch me in the face. KIDDING!
But yeah, we just keep fighting over whatever package we want until time is up or we run out of claims
When the claiming period ends, the last person to have successfully claimed Package B gets that craft, and the other person gets another craft (say you originally had Package N and I had Package B. When you claim Package B, you would be giving me your Package N. They just switch back and forth).