I have considered the option of mountain bike gearing on my bike as well (I don't do well on hills) but have not done it. My first try at "helping" myself with the gearing (I, too, have a triple - 52/42/30) was with a 12/27 cassette on the rear. I swapped out the rear cassette last spring and it did help, though not as much as I would have liked.
This fall I rode a friend's compact double (50/34) with an 11 or 12/25. Climbing the same hills on that bike seemed easier - would someone please explain to me why?? I am confused but now considering switching to a compact double with a 12/27 cassette.
Kathi - you and I both have a lot to learn!
"When I'm on my bike I forget about things like age. I just have fun." Kathy Sessler
2006 Independent Fabrication Custom Ti Crown Jewel (Road, though she has been known to go just about anywhere)/Specialized Jett