Google Might Gobble
Technorati - If Google is the average person's homepage, Technorati is the homepage of the underground, tech-savvy web user. Technorati is a blog portal whose average visitor enjoys podcasts, Wikipedia, and the Daily Show with Jon Stewart. Providing more cutting edge results than a normal search engine, Technorati would integrate well with Google News and/or Blogger, and could perhaps feature blogs on the Google Personalized Homepage. Technorati is somewhat similar to Bloglines, which was purchased by Ask Jeeves recently.
Buzznet - Yahoo! beat Google to the punch by acquiring Flickr, one of my candidates in the first draft of this article. Like Flickr, Buzznet is a photo hosting and sharing service that features unique tagging features. It is possible to browse by tag and see all sorts of interesting stuff. Buzznet would probably jibe with Picasa's Hello photo posting service, perhaps include some sort of photo-Blogger, and integrate well with Orkut.
Koders - Koders is a search engine for open source code that works remarkably well. With the recent push for plugins for Google Desktop search, Koders would be an interesting addition to Google's software initiatives. It would make sense to combine with Google Code and Google Linux Search in some way.
GuruNet (Answers.com) - Recently, Google stopped linking to definitions on Dictionary.com, and started linking to Answers.com instead. Answers features a wealth of information about different topics, and uses Wikipedia for much of it. Since Wikipedia's non-profit status rules it out as a potential Google acquisition, Answers.com would be the next best thing. It also would help improve Google Q&A quite a bit. Interestingly, GuruNet is a publicly traded company (AMEX: GRU) with a market cap of about $100 million.
del.icio.us - This social bookmarking and tagging application could be used to improve Google search results, and perhaps integrate with Orkut in some way. Were Google to buy Buzznet as suggested above, this would work well with it.
StumbleUpon - This unique browser plugin and service would probably improve Google results and add a new level to the venerable search engine. It would probably combine with the Google Toolbar in some fashion, since the two have some similar functions.
Propel - Similar to Google Web Accelerator, Propel claims to speed up your browsing experience. The company is run by optical mouse inventor Steven T. Kirsch, who is no stranger to buyouts: his Frame Technology Corp. was purchased by Adobe, and his Infoseek was bought by Disney. This could help Google out with Web Accelerator, which it has been having trouble with.
From Left Field
Here are some companies you probably haven't heard of, and some companies you know very well that fit in less well with the Google plan. It is not too likely that any of these will be bought by Google, but keep in mind, most of Google's past acquisitions have been unexpected.
Audioscrobbler/Last.fm - So far, Google hasn't made any inroads into the music industry. However, these sites together form an interesting, Google-ish service that uses algorithms reminiscent of PageRank to calculate the top artists and similar info.
TiVo - TiVo is a little too big and a little too well-known to be bought by Google. Also, Google's experience with hardware is limited to Google Search Appliances and similar. But, TiVo would work well with Google Video. TiVo seems to fit better with Apple Computer's media plans than it does with Google's geek mentality, though.
Icosystem - This swarm intelligence company might be useful for radical new spidering algorithms or some new form of PageRank. It's only peripherally Google-ish, though.
Monster - Monster is the most popular job search site. Some bloggers have tossed this idea around, touting various forms of integration with other Google services. They also mention that Yahoo! owns HotJobs. However, one wonders whether Google is interested in this market at all.
Coral - This caching service would probably be interesting and useful for Google's own cache. However, it is run by NYU, so it's not a commercial company, and may not be up for grabs.
The Open Directory Project - The definitive web directory has long been partnered with Google for the Google Directory. But the Google Directory hasn't been updated in a very long time, and it still sports the old tabbed Google design, which lacks links to Froogle and Google Local. Although the ODP is owned by Netscape, Google should have sufficient cash to acquire it since the IPO.
Stayhealthy/Fitness Expert - This online health company doesn't offer content a la WebMD, instead providing health and fitness hardware, self-test kits, and a kiosk joint-ventured with IBM. The hardware interface is web-based. As with TiVo, Google's limited hardware experience may be a problem, and one wonders whether Google is interested in the health and fitness space.
World66 - World66 could be Google's answer to Yahoo! Travel, with some work. Its Wiki style, however, might be too wild for Google's liking.
My Way - This image ad and popup-free page is very Google-like. However, it's redundant to existing Google offerings, and these days having no popups isn't as big a deal as it was 3 years ago. It might compete with Yahoo!'s portal, though.