If you buy electrical, mechanical, and optical components, this site is a handy way to find the parts you need. The form-based search interface is customized for each kind of part (accelerometers, opamps, EDFAs, FETs, pressure sensors, etc.), results are tabulated for easy comparison, and links to vendor documents are provided. Some features require free registration.

"Built for engineers, GlobalSpec.com provides instant access to over 590,000 electrical, mechanical and optical components. Forget that time-consuming catalog process. Our engineers standardize parts data across suppliers so your online search results are thorough, up-to-date, accurate - and immediate."