On the subject of rotting things ...
... It is far better for your lawn (and all concerned) to simply mulch the leaves into the grass than to bag them and haul 'em to the land fill.
I've found that mulching leaves into the grass helps accelerate the decay of the thatch that builds up in the lawn. The areas of the lawn that get covered with leaves seems require less water during the year than those that are clear of leaves.
If you don't like the look of leaves on the grass, then I such piling the leaves in a mulch pile ... that way you will get great free mulch each year.
On the subject of mulch, I've come across a number of sites selling organic earth worms for mulch piles.
This is very important. DO NOT BUY EARTH WORMS! Gardeners do a great deal of damage to the local ecosystem when they import composters. The native composters of the Western US do every bit as good a job composting as earth worms imported from Europe.
Composters play a key element in the ecosystem. Importing a composter (ie, buying earthworms on line) does as much damage to the local ecosystem as any invasive speces.
If you wish to find a starter for your mulch pile, I suggest going to a local abandonned field or taking a walk in the mountains and picking up a back full of partially rotted leaves. The chances are better than things found in local nature will have local composters.
You may not have noticed, but the Wasatch has some areas with extremely fertile foot thick loam. The fertile soil of the Wasatch gets destroyed by imported composters. In making my mulch pile, I actually went into the mountains and grabbed bag full of half rotten leaves from an area with rich soil hoping that I was picking up native composters. I would avoid ordering worms or composters over the Internet as such things are likely to make their way into the native ecosystem.
In conclusion, mulching is better than hauling quality organic biomass to the land fill. A yard covered with leaves is the new eco-chic.