The Summer Olympics started in 1896 but the first Scottish medals didn't come until 1900 when they won silver and bronze in...golf of course. (Golf is no longer an Olympic sport today by the way.) Their first gold came in a big way in 1908 when 5 Scots brought home the gold in steeplechase, 400m, coxless fours (a rowing event), water polo, and 12 metre class (sailing). And home wasn't far away as the 1908 Olympics were in London.
Since than, there's been a Scot who has medaled in just about every Olympics. The only one's they didn't medal in were 1932 and 1936. There were even some Scots on the 1920 tug of war team that brought home the gold...obviously no longer an Olympic sport, but it brought a smile to my face :)
There are many notable Scottish Olympic athletes. Track star Eric Liddell of Chariots of Fire fame of course. Shirley Robertson picked up 2 gold medals for sailing in the 2000 and 2004 Olympics, the only Scotswoman to have ever won 2 gold medals. And Rodney Pattison is the most decorated Scottish Olympian, winning 2 golds and 1 silver medal between 1968-1972.
The official website for Great Britain's 2008 Summer Olympic team is a bit confusing. You can search their athlete's by country, but the results include both country of birth and country of residence. So while they list 25 athlete's as being from Scotland only 18 were actually born in Scotland. Two were born in other countries but basically grew up in Scotland. Mostly men (there are only 5 women) Scotland is represented in swimming, canoe, rowing, shooting, cycling, steeplechase, track, tennis, kayak, triatholon, and field hockey. Their dominant sport is swimming where they have 5 athlete's competing.