I know I've said this before, but I'll say it again, it takes me about the same amount of time to complete my workout at home as it would to even get to the gym itself. And the clincher is that I can get just as good of a workout in my tiny room with a very small set of weights. Heck, you don't even need weights. Check out Drew Baye's Project: Kratos for information on how to workout with just your body weight. I've managed to put on some muscle the past year or two by simply upping my intensity and refining my technique.
I realize working out at home is not for everyone though. I'm sure some people even feel that PAYING for a membership is necessary motivation to get them to the gym for a workout. To each their own I suppose, but I'm here to tell you that gyms are not REQUIRED in order to work yourself into top physical condition. What is required is consistency. If you challenge all of your muscles in a safe, effective manor, on a consistent basis, you will be stronger and better able to enjoy the rest of what you do in life. Amen.
I'll finish with a quote from one of Drew's blog posts:
Whether you train with machines, free weights, body weight, manual resistance, some other tool, or a combination of all of them, the strength gained will transfer to all movements the muscles trained are involved in. You just have to plan your program so you effectively train all of the major muscle groups - Drew Baye
PS Check this out. Considering a monthly fee of $85 (yes, the cheapest in Aspen) from Nov. 2009 to Nov. 2013 I 'saved' $4080 by working out at home.