DigiKey OpenSearch Plugin
I was doing the first of many parts orders from DigiKey, a massive online supplier of electronic components, for the semester, and finally decided to make an OpenSearch plugin for Firefox. This lets you search for DigiKey parts from the search bar in the upper-right corner of OpenSearch compatible browsers. I've only tested this in Firefox 18.104.22.168, and I'm pretty sure that it won't work in IE7 (surprise!) because IE7 doesn't support POST requests for OpenSearch plugins. Get Firefox.
The format for creating these plugins is a very straightforward XML file. You can find the docs on how to create your own on developer.mozilla.org.
NOTE: This plugin is in no way supported by the Digi-Key corporation. Please do not bother them with help requests if it doesn't work properly (probably because you are running IE). Contact the author with any questions or problems - at which time I will probably just tell you to Get Firefox.