InChIMatic, as described previously, is a new service that lets you perform exact structure searches on the Web using Google. A new version offers searching via several other search engines and features a streamlined interface. The screenshot below shows the the current search engine options with 1-bromonaphthalene in the editor window.
There are noticeable differences in the abilities of search engines other than Google to find InChIs. Google seems to offer the most complete coverage. For example, all search engines I've tried have returned either a subset or recapitulation of Google's results.
One of the most striking things about InChIMatic is how specific the search results are. Every molecule that has produced results for me has been a direct hit. Also notable is how few InChIs are currently indexed by Google and other search engines. Tackling that problem will require a convenient and unobtrusive way to get InChIs into Web pages and to get those pages indexed by search engines. But more on that later.