I came across a link to a site called 'Virtual String Art' some time ago and filed it away. I came across that file and visited the site again, recently. It doesn't seem to have been updated lately - the front page seems to wish us 'Happy Holidays 2000'! However, it can still be used to produce some interesting patterns. It is a way of experimenting with Bézier curves.
String art might be seen as somewhat childish. It has been used as something that children can play with to produce interesting patterns. However, it does have a more serious artistic pedigree. It was used by Naum Gabo (1890-1977) who used nylon thread and fishing line over a perspex frame. Some of his work can be found at the Tate Gallery. See, for example, Linear Construction No.1 (1942-3).
Although the curves produced by straight lines are now named after Pierre Bézier (1910-1999), Gabo's work obviously predates his association with these curves which only dates from the early 1960s. (Whatismore, Paul de Casteljau (1930- ) also seems to have had priority over Bézier in terms of having produced the original algorithms still used to produce these curves mathematically.)