A short while ago I mentioned that Barry had met a lady in the forest who was dog scootering. He thought it might be fun to try it so started researching.
It's similar to sledding – in fact the dogs wear the same harnesses but are attached to a scooter rather than a sled. Sometimes people use a bike rather than a scooter – officially this is called bikejoring – but it is considered more dangerous as it is much more difficult to dismount a bicycle quickly in an emergency.
It is a sport growing in popularity. In the meantime we are musing on the subject. It does look like a lot of fun and certainly Frodo would be a candidate as he's very strong. Apparently most dogs can be trained to the harness – I have my doubts about Chihuahuas though!
There is a video clip here.