Remember to get their name and address, as well EIN / SSN so that you can actually fill out the fields in the 1099 form. And even if it's below $600, you _might_ buy from them before the year-end, so you need to record the amount in case the total aggregate amount for the year goes above $600.

This requirement is just plainly insane, but at least IRS also agrees that it's insane ( http://www.irs.gov/newsroom/article/0,,id=225270,00.html )