As of yesterday, Google offers the ability to search US patents (www.google.com/patents). It is text searchable back to at least 1836, and very fast! You can even view images of original patents online.
(On the downside, you can not search abstracts alone or published applications, but that does not matter so much if you are just searching for interest’s sake…)
Here is an excerpt from Google’s press release on the subject:
We’ve all heard about the Wright brothers, Thomas Edison, and Alexander Graham Bell — famous inventors whose creative minds changed the course of history. But there are many more like them, and millions of inventions that have been patented in the U.S. alone — from useful everyday items such as adhesive tape and contact lenses to, er, things useful in specific situations, like this shark protector suit or this amusement device incorporating simulated cheese and mice.
Today, we’re excited to be releasing the beta version of Google Patent Search, which makes it easy to search the full text of the U.S. patent corpus and find patents that interest you. Start your exploration at http://www.google.com/patents or visit the Advanced Patent Search page to search by criteria, including patent number, inventor, and filing date.
Should be fun! Happy searching!