It is believed there have been more major inventions from the Scots than any other country in the World, if you are looking at inventions per head of population. Here is a list of some:

Field of Medicine:

John Williams, born Glasgow, developed the vaccine against smallpox.
Alexander Fleming, born in Ayrshire, Scotland, discovered penicillin.
James Simson, born Bathgate, was the first man to use chloroform.

Field of Communication/Electronics:

Alexander Graham Bell, born in Edinburgh, invented the telephone. John Logie Baird, born Helensburgh, invented the television.

Field of Transportation:

James watt, born Greenock, Scotland, invented the modern steam engine, while William Symington born in Lanarkshire, was the first man to propel a boat by steam.
John Boyd Dunlop, born Scotland, patented the pneumatic tire.
John Loudon MacAdam, born in Ayr, invented tarmac road surface.
Kirkpatrick MacMillan, born in Thorhill, invented the bicycle.

Miscellaneous:

Charles MacIntosh, born in Glasgow, patented the raincoat.
John Chalmers, born in Dundee, invented the adhesive stamp.
Patrick Ferguson, born in Scotland, invented the breech-loading rifle.
Mrs Keiller, born in Dundee, invented marmalade.