I had one of these cups when my son was a baby, they come in blue, green or pink and currently retail on Amazon for £2.59 (July 2012).

The cup is made of BPA free plastic and is pretty easy to use, it is designed to be used from 4 months upwards and has small handles on either side to allow your baby to grip the cup, it has a flip up lid that is easy to use, but leaks a bit if you put the cup in your bag, it can be put in a steriliser and has measuring lines running up the side to allow you to dilute juice to appropriate measures if you wish.

I found that the cup was good for my son, he soon mastered using it, I would a first only put a small amount of water in the cup so that it was not too heavy for him to lift and also so he did not bang it into his face. The cup and lid are easy to detach and can be cleaned easily with a bottle brush. It is quite fast flowing as it is supposed to encourage sipping rather than sucking, which is supposed to be better for your baby. The water will spill out if he/she shakes the cup around, but that's too much of a problem.

We started using the cup at around 5 months and now at 2 years old, my son will still occasionally still drink out of it, rather than a cup without a lid, especially when he is tired.

Overall I would recommend this cup to others as it is easy to use and clean and is well priced, the only downside is that mine leaks if I put it in my bag.