Luge is the only L Olympic Sport and although it's one the oldest winter sports it didn't make its Olympic debut until 1964. Luge is French for sledge and that's all it is - a sledge, with no brakes, that hurtles down a track at speeds of up to 140 km/hr (87mph) and no protection! (Apart from a crash helmet.) Maybe that's why I've never wanted to be a sportsperson. I've never understood the mentality of a person that would put themselves in that situation.
Understandably it's not a sport that GB excels in as athletes have to train abroad where tracks are situated. Artificially created tracks are refridgerated to keep the temperature constantly low and the run smooth.
It's another sport where progress has been made, not only in the way the sleds are designed and the weight allowances that can be factored in, but also that timings are calculated to thousandths of a second. I can't imagine how gutting it must be though to miss out on an Olympic medal by that tiny margin of time.
Another L sport that has been around for a long time is Lacrosse but judging by the amount of protective gear players wear it looks pretty risky to me. I have a history of accidents involving sports with balls and sticks so I would give Lacrosse a wide berth.
A more modern sport is Laser Tag - think electronic Paintball - less painful too and despite its name it uses infra red beams not lasers. The indoor versions which usually involve less running around and no roughhousing might suit me better but then it would help if I could actually hit a target I'm aiming for.
If you're looking for an obsure L sport then it has to be Letterboxing. A bit like geocaching but without the satellites! It combines elements of orienteering, art and puzzles. Originating on Dartmoor in the UK it has spread around the world. It involves finding "Letterboxes" which contain a log of previous finders and a stamp that you can use to keep your own log of boxes found. Clues to the Dartmoor boxes are made available twice a year. Definitely sounds more like my type of sport! More info can be found here.