I have tried the Birdy folding bike - and know a few people who use them all the time - they feel much more like a real bike to ride than the other types - which tend to drive more like a scooter.
The Birdy folds up in a few seconds (it really does!) and is about 9kg I think.
There may be a few other folding bikes out there that are also OK, but as far as I am aware the ABirdy would be the best one - especially for travel.
Weighing 110kg may be the only drawback - I am not sure if it has a weight rating or not.
I just know when I tried it I was very surprised at how good it felt.
Worth a test ride anyway....