Technical symbols in many categories for AutoCAD and Adobe Illustrator, as well as diagramming and title block management tools. http://www.codezebra.com/
A collection of AutoCAD DWG blocks, including people, trees, cars, trucks, boats, construction details, and hatch textures, as uploaded by contributors. http://cben.net/
Selection of downloadable AutoCAD drawing blocks, fonts, hatch pattern, and AutoLISP routines, for download based on the shareware concept. http://www.insa.com/files.shtml
A collection AutoCAD details and blocks on CD for sale, for interior designers, architects, and students. The DWG files are both 2-D and 3-D. http://www.designforward.net/