If you can stand it, here's one more point on the reading numbers issue. All of this talk has made me wonder about what those symbols (a dot, a four, and a five) really mean. The fact that we always assume base ten jumped unbidden into my head. The real way to say it might be "radix point 4 5 base ten". Now, I am not suggesting that we teach it to kids this way, just a) noticing an interesting aspect of this discussion and b) reiterating that there must be some balance between convenience and conceptual correctness.
It also might be a fun thing to think about what .45 is base six, for example. Maybe some students would get a "bigger picture" of what the radix point means if they could see what it meant with other bases.
And as long as I'm dreaming, I'll just go ahead and pretend we have the time to go off and explore things like this with students...
Actually, concerning that point, how many of you teachers feel like the number of subjects you are supposed to "cover" inhibits the time you have for exploring? Is this something that should be considered in education reform?