There have been studies that have shown that co sleeping is a good method of avoiding SIDS, it's all to do with the mother and baby being in tune with one another apparently (I can't remember the exact reasoning behind it). Also taking baby to a home that is smoke free and even sleeping baby in the same room as you can help. The biggest thing is not so much where they are sleeping, but how they are put to bed - on their back, towards the end of the bed (if using a cot) and not too many covers over them. If you go to the sids for kids website they have some guidelines there.