I'm not sure that I think there's a direct comparison to hardness and dent resistance, but the crush test is spot on. I'll admit that my material knowledge isn't significant, even though I hold an engineering degree, but I think that there are far more significant factors.
I'd like to see the crush test examined to include a long section of tube. If you used a piece long enough to eliminate any end constraints and loaded it at the center it would be the closest approximation of a dent.
Also, some impact testing vs. controlled applied loads might be in order. I realize that it's difficult to calibrate a hammer, but you could simply drop a specified weight from a specified distance.
Also, does bending have any effect on the dent resistance. How about the same tests on a bend?
I think your on the right track and am only offering a few other ways to get additional results.
blackdiamond-
These are excellent test ideas! It has been requested to run the crush test using longer samples and I plan on doing this soon.
Your testing of bends idea is excellent but I must come up with a way to cradle the samples without allowing any movement at the support to get consistent results. I probably don't have matching bend angles to play with (remember we currently have a limited amount of competitor's material to play with) but we could match bends for this.
Another test I can very easily do is a tensile test with a strain gauge. This will tell us how much deformation each material can withstand before deforming, and will give us elongation, necking, and yield stress numbers to compare. It takes more time than I was allotted so we'll have to see if I can run some other tests at the same time to make my time worthwhile.
All I know is that you guys are teaching me a whole lotta stuff that I did NOT know before. This thread is entertaining as well as informational. Keep up the good work(battle). 
Thanks man! This is the first time I've ever done testing of this kind and I think it is beginning to pay off. I have already pissed off a lot of people which means I am doing something right!!
BigMike
