Evan,
I agree with Lynn, those tubes make for an amusing visual.
I read the post from the semponium thread, it's an interesting concept that fertilization at lower temps could induce a more coldhardy offspring, it does seem like there may be some problems there though: Firstly, Sempervivum bloom predominately at or around the peak of summer, so you'd have to subject them to artificial temperatures during hybridizing to take this theory to it's maximum effect. Another concern I'd have is that at some temperature I'd imagine all pollen would go dormant, so you'd have to moderate, possibly to the point where it ended up not making a difference. Sure I think an Aeonium bred in an Oregon summer might naturally be slightly more cold tolerant than one bred in the tropics, but if such a difference still wasn't enough to get a hybrid to survive a winter it's hard to say how many generations it'd take to get one that does, and you'd still have to test the offspring with the weather anyways. I don't know, it's an interesting thought, I'll have to brood over it for a while.
I made a cross during the winter on two latent blooms and have actually sprouted seedlings from the cross, it was 'Silverine' x 'Thunder', thunder mostly produces winter weak offspring, so if these seedlings are tougher than expected that might ascribe some validity to this notion.
As always, thanks for the food-for-thought,
-Sol