Custom component I am developing now. Google provides you with a couple snippets, one for the search form and one that dipslays an iframe of search results.
I put the search form in a module and the results in a component.
I modified the standard Joomla Email link for the 'Share It!' feature.
I got the javascript snippet of code from an Apress book. It opens the window in an iFrame instead of a popup.
You can see the javascript files in the head of the html and the associated styles in main css stylesheet. I had to edit the content component, disabling the popup and adding a class to hook the javascript.
Still need to debug display in IE7 and Safari and the problem with displaying and closing multiple iframes at once.
As for offering a component to the community I haven't thought about that yet, it depends on where we take the development of it. Right now it is just storing searches in a table. We may tag these down the line.
Just completed a template redesign, coded from scratch on this site. What do you think? We've found that designing for 1024 width looks great on most machines and allows for a nicer interface.