Yikes! I thought those small black bits on my light gray carpet were sweater lint - but they're black grease! I think they are from using my bike on the trainer - I put a mat and towel under it, but it looks like I have sent some grease flying a few feet behind the bike. My landlord (who also happens to be my dad) is going to kill me! Any hints for getting up at least some of these black stains without spreading them around? I haven't tried anything yet because I'm afraid of turning a small spot into a bigger one. (I have berber carpet - the worst!)