This is an interesting question that I ask myself every time I am 8 miles back in the woods carrying my tripod. While there are many people of will most certainly disagree with this statement, use a tripod. Every time I choose to be adventurous and not use a tripod I get the greatest perspectives and love the freedom to frame the shot how to I choose, but I never like the finished product.
If I shoot HDR or if I have low light conditions the far away objects are not clear and I am unhappy with the sharpness unless I use a tripod. There are few things more dis-heartening then to have the perfect shot on the LCD but after you process it, it goes in the recycle bin.
High ISO shots are hard to keep the noise down in and lowering the aperture to increase your shutter speed will cause you depth of field to be too shallow. There are many who will disagree with the choice to use a tripod, it really is a personal choice.
They say digital removes the need to have a tripod. I have been shooting digital for 15 years and only started using a tripod consistently for the last two years. My photography it better for it.