I run a "dinglespeed" in the winter. My 29er SS has 33/36 chainrings up front, and 22/25 cogs in back. Thus a 33/25 set up for easier pedaling when it gets a bit tougher going, or the 36/22 when everything is moving fine. Just a thought. As long as the teeth add up the same, you can change it back and forth without any tension issues.
I thought about a dingle setup but my budget won't allow it. My commute is 8mi one way and I've been riding a singlespeed for about 5mos now so muscling through hills wouldn't be much of a problem and I'll be on the street most of the time. Thanks to all who has replied!