http://www.tomatoville.com/showthread.php?t=18090
I think the above link to here at Tville should answer some questions being asked.
And yes,I used to freeze tomato seeds but before doing so you put in your bottle or whatever,that's what I used,discarded Scintilation bottles,you have to put a dessicant in the bottle, many meds come with those wee packets, and dry the seeds down to about 6 to 8 % moisture content, and you test for that by using NOT litmus paper (pH) but similar but similar paper strips that indicate moisture level.
SSE keeps some frozen seeds at SSE at minus 20 or so,but also sent backup seeds to I think it was Cheyenne, WY where they were kept in large metal cylinders at I think minus 80F Centigrade.
IMO what it comes down to for each person is how long they want to freeze seeds. For next year, doesn't make sense to me,just put some seeds in a #1 coin envelope and just seal it shut with tape and keep at ambient room temp. 3 years, 5 years,etc.? That's a decision that only each person can make.
It's also good to know that with regard to tomato seed that heart varieties in particular don't remain viable that long. And yes, a search here at Tville exists where that was discussed.
Aha,if storing them at home in a fridge freezer,thaw out the bottle they are in to room temp, before removing a few since if you don't do that moisture gets in and that's the way to end up with moldy seeds.
My best save were 22 yo seeds of September Dawn that were sent to me and just stored in a garage in a glass canning jar,with a label on the jar re the info I just gave.
Carolyn