If you really want low gears check out this Quad Chainring Setup:
http://www.abundantadventures.com/mt_triple.html
I plan to use one of these Quad Chainrings for my recumbent bike I'm building. I figure 20, 30, 46, 52 tooth chainrings would give me 16 to 120+ gear inches on a 26 inch wheel.
4 Chainrings * 6 gear cassette = 24 speed. Not too shabby. If you mod the front derailleur you could have 5 chainrings * 6 gear cassette = 30. Your now in 10 spd cassette territory! Here are better photos of the Quad and Quintuple Chainrings.
http://www.abundantadventures.com/mt_plus.html