Hope you find some of these sites and tools useful…
TRAIL – Technical Report Archive and Image Library – a new initiative sponsored by the Greater Western Library Alliance (GWLA) and the Center for Research Libraries (CRL), to digitize and provide free access to federal technical reports prior to 1975. The PDFs currently available on this site are crisp, clear, and very readable. URL: http://digicoll.manoa.hawaii.edu/techreports/index.php (Thanks to Jay Bhatt at the Drexel University Library for his blog posting reminding me of this service).
Google SketchUp – one of a number of very useful and free Google Tools, this latest one provides free software for creating and sharing 3D models. This might be useful as a tool in engineering design classes. The basic software is free to download and use, the more advanced software (SketchUP Pro 6 costs $495). URL: http://sketchup.google.com/
PAIR – Public Portal to Patent Applications – I learned about this from a presentation by Charlotte Erdmann (Purdue University Library) at the ASEE Conference in Pittsburgh, PA. This search tool enables the researcher to view relevant documents in the patent application process. URL: http://portal.uspto.gov/external/portal/pair