Regarding screen scraping, you might find this work “Sifter” interesting:
http://www.vimeo.com/808235
Regarding data integration, see “Potluck”:
http://www.vimeo.com/808214
which has been blogged about by Jon Udell:
http://blog.jonudell.net/2007/12/06/simile-semantic-web-mashups-for-the-rest-of-us/
And regarding creating mashups, see “Exhibit”:
http://simile.mit.edu/exhibit/
Some of these projects dated back quite a few years.