Hi garbird - we have a great FAQ here about cross-pollination that should answer all your questions. I have linked it below for you.

If after reading it you still have questions, please let us know.

Enjoy your tomatoes. ;)

Dave

Here is a link that might be useful: FAQ: Cross Pollination in Tomatoes

Thanks, Dave. How did I not notice the FAQ before. I've been here for a while, I usually just do a search before I post, and if I don't find the answer I'll ask.
That was great.
Thanks again,
garbird

NP - so did it answer all your questions?

Dave

I just wanted to address one of your questions not specifically addressed in the FAQ.

"Unless hybrid tomatoes don't produce viable pollen?"
Hybrid plants do produce viable pollen or they wouldn't be able to produce fruit. The fruit has seeds and those seeds are viable if saved and stored properly. Therefore, it is possible, but not probable*, that a hybrid planted in close proximity to an open polinated/heirloom variety could cross.

*Note: My experience agrees with the 2%-5% figure used in the FAQ.

Good luck.

Randy

Thanks guys. I've learned a lot about tomatoes in the past couple of days. I am going to try to bag some of the flowers so I can save the seeds only from those. I hope it works these seeds were a gift from a man whose family is from Russia, and it was the only variety that they ever grew. My cousin had some a few years ago and let them cross with something else, and the seeds he saved did'nt come back with the original characteristics of the heirloom plant.
Thanks, Garland