Sugru is like slightly toxic plasticene when you first get it out of the box, but it sets like strong rubber. In fact it was perfect for this, the finished feet feel securely attached and they're slightly squishy so they absorb the shock of me typing or the issues of a slightly uneven surface. Perfect!
I have a small netbook that I use for events, which I've had for a few years and keep upgrading with various bits and pieces. This year, all the little rubber feet had dropped off so if you put it on a surface, it kind of slid around, which was annoying. It occurred to me that I'd bought some sugru at Maker Faire this year, so I broke it out and made new feet for my netbook (and a little keyboard where the same thing had happened)