I bought these for my baby daughter after she enjoyed using them in a music class. I hesitated as I though that £10 was quite expensive but I'm glad I got them.
She loves all the colours, we dance around at home with them, but the absolute favourite is peek-a-boo. The scarves are great for this as they are transparent and breathable, so much less scary for a baby than putting a muslin over their head and they have the added bonus of turning the world red/green/purple for her!
It's a great way to encourage interaction, and works both ways - relatives who are a bit rusty at dealing with children will also find themselves being drawn into the game.
They are easily scrunched up into a bag so as a toy very transportable and other kids love them too. They don't come with washing instructions but I have put them through the washing machine several times and they are fine.
I looked at different sizes before buying and I'm glad I got this size (I also bought the 40x40 versions from Firetoys for party bags and these ones are better). I would buy these again but rather than getting all 6, I would probably try to split the cost with another mum and just have 3 each.