I saw a child seat on a Brompton

[T4tomo]

Thanks, yes my boy is two and a half.

Awesome. Not a cheap solution but the engineering is pretty cool.

I've use a similar (sit in front seat) albeit not on my Brompton, on an old MTB, with just a seat and foot rests. It works well, child feels secure as they are "within your arms", can see whats going on and its real easy to chat to them whilst riding (unlike a "behind" mounted seat were the child gets to stare at a sweaty back).