I came across the Scottish Emigration Database recently which is a project based at the University of Aberdeen. It contains the records of over 21,000 passengers who travelled from Scotland for non-European ports between 1890 and 1960.
At NLS we have rich collections of material relating to the emigration of Scots which complement resources like these. Our Scots Abroad web feature tells six stories of emigration from Scotland between the 1770s and the 1930s as well as containing information and links to other emigration resources. Also, our Scots Abroad databases give details of material relating to the lives of Scots overseas and the variety of reasons they traveled abroad.