I use my coffee and spice grinders a lot, and I find that they are almost impossible to keep clean. When you're grinding just one thing, like coffee, this is not too big a deal. An occasional swipe with a paper towel is fine.
But cleaning a spice grinder is another story. Spices have oils that are released by toasting and grinding, and these can build up on the grinder, muddying tastes. This oil and the dust that begins to coat the blades and inside of my grinder are hard to remove. The grinder can't be washed, so I would clean it out painstakingly with a damp towel.
Then I learned a quick trick for blotting up those oils and spice fragments. Put about 1/4 cup of rice in your grinder and grind for about a minute, or until it's pulverized into bits. The oils cling to the rice, leaving behind just a thin dust of rice flour which is easily wiped out. It won't return your grinder to a pristine state, but it's a good method for weekly or monthly cleaning and maintenance.
Anyone else have a good way to clean a coffee or spice grinder?
Floral Drink Dispen...

Put a small piece of bread in the grinder and run it through -- similar to the rice idea but possibly more absorbent.
for coffee, clean it with sugar and use the sugar in your coffee. for savories, clean it with salt and use the flavored salt. you get the general idea...
I used to just grind my coffee and then ignore whatever was left in the grinder. One day (after years), something possessed me to try to clean it out, and I discovered that the oil in the coffee beans had turned the grinds into sticky grossness. So after I gouged it all out, I gave in and bought one of those little coffee grinder brushes. I brush the grinder out every time I make coffee, so nothing builds up, and it's now safe to drink coffee at my house again.
And actually, for everything other than coffee, I've got a grinder that splits apart, and everything except the motor section goes in the dishwasher.
I only have one grinder. Coffee and spices both go into the same device. I sometimes add a little bit of baking soda to my rice when I clean it after griding spices, and never notice anything in my coffee.
However, there was the time when a guest asked: "Is this coffee SPICY?" and I realized I'd forgotten to clean it after griding chipotles. :)
try grinding a piece of bread, or several, until
the oils and odor are gone.
Great ideas and thanks! I use my little Braun grinder for flax seeds and other things, and these tips will come in handy for sure.
For Burr coffee grinders, there's a commercial cleaner:
http://www.wholelattelove.com/Urnex/grindz.cfm
I usually run rice through the grinder until it comes out clean. Then, I'll do a test grind with a small amount of beans to finish.
I have a set of two silicone brushes I got at the dollar store which I use to brush out my grinder every time. The nice thing is that after I use the brush, I just toss it in the dishwasher.