The Baba+Boo wetbags are one of the best we have found at such an incredible price.
The small size is perfect for washable wipes, the medium is ideal to put in your changing bag to store dirty reusable nappies when out and about and the large are a great alternative to the washable nappy bucket, many have them for nursery/childminder, nights away.
They are also great for other scenarios and we have sold them to those who don't have babies in nappies, they can be used to store toiletries when away on holiday/camping, sunscreen in your handbag (if that leaks it can be a disaster!) or any other situation where you need a waterproof bag. They come in a range of colours/patterns so there is bound to be a design to complement your nursery scheme.