Officially, no. If it's a repeat buyer or someone I "know" from a board or someone with lots of good feedback who asks nicely before paying, I've made exceptions.
If it's a buyer who just assumes they can send one, even though I don't list it as a payment method, I've refused them. Occassionally I'll deposit a small one, but they have to wait for me to go to the bank at my convenience and then wait a reasonable clearing period.
I don't really care to track their clearing, but the biggest reason I don't take checks is I don't go to the bank very often. It's not worth the inconvience for me to make a special trip to get a check in and start the process.