My friend, Matt, is so smart. He just gave me some tomato seeds that he saved in a unique way:
He just scooped tomato seeds onto labelled index cards, guts and all. Then he let them dry. When it's time to plant them, you just need to flick the seeds off the card. He was careful with the seed cards. He stored them in a paper envelope. I was a little more careless because I transported them to my house loose in my purse. I lost a couple of cherry tomato seeds, but not many.
Too bad I didn't have more varieties which seeds fell off in my purse. I would have played the tomato mystery game by planting the seeds and trying to guess which tomatoes would come from which plants. This is similar to the game that I play in the spring with the volunteer tomatoes in my garden.
We had a strange coincidence last year. When it came time to trade seeds, we ended up having 8 of 10 of the same heirloom varieties. We didn't plan our seed buying in advance and we bought from different sources. This year, we only have a couple of varieties in common.