Keeping animals out of babies room

Not sure about keeping cats out of the room entirely, but I have heard of a good way to keep them out of the cot.

Set up the cot and blow up balloons and put them in the cot, that way when the cat tries to climb in she/he will pop the balloons and get scared off. Plastic bags often works well too.
Our cat loves sleeping on soft stuff too.

Our cat is a very old girl and loves sleeping on anything soft and warm too. I set the basinett up in our bedroom about 3mths before Oli was born so that she could get used to it. She had a good sniff, but never really took an interest in it. She jumped into his cot once, but that was only because silly mummy left a chair next to the cot as a handy step for her! She got a stern bollocking and has never been back in. I think she hates the screaming - so that puts her off!