When I was trying to wean my children, I tried different brands of bottles, hoping that the different shapes and textures of the nipples would make it easier.... Little did I know... it was really hard! For my second child, I was in France and my niece was drinking from a bottle that I had never seen in the US before : the MAM bottles. The ultra-soft silicon nipple was really different from the "round" ones I had tried before (even the ones that supposedly mimic the natural nipple). We tried it with my child and it was an immediate success. I later recommended them to my sister who was looking for bottles for her child and she has been really happy as well.
The MAM bottles are quite ubiquitous in France these days and I was happy to see that you can now find them in the US (www.drugstore.com or www.amazon.com). They might not be the perfect bottle for everyone, but at least they worked with the families who tried them around me for both infant and older children.
MAM bottles are designed to be anti-colic through vents at the bottom of the bottle; they are also BABY SAFE; BPA, lead, pthalate, and PVC FREE!
From my experience, for children who have been breastfed, and hence used to a rapid flow of milk, it's best to use the "MAM Nipple X" rather than a numbered one. My child was struggling with a Number 3 nipple; so I switched to the MAM Nipple X which allows a faster flow.
Just thought that you or your friends might be interested!
For more information on the MAM bottles and the other produces (pacifiers, sippy cups, etc.) visit http://www.mambaby.com/