Not sure how to best dispose of the fat or grease from your last cooking adventure? If the fat is bacon drippings, I would recommend keeping it for later use, but that's a Tasty Tip for another day. (Throwing away all that useful goodness is almost sacrilege where I come from.)
However, if the fat is of the kind you would rather just toss (i.e. from ground meat, etc.), line a mug or bowl with aluminum foil, pour in the fat, and allow it to solidify. Once the fat has set, just pull out the foil and discard. Easy peasy! And you won't have to worry about a clogged sink drain!