It has been a challenge but I've tried not to jump on the bandwagon when Google unveils yet another tool (e.g. Google Spreadsheets, Google Base, etc.) but I have to admit the news about its newest creation from Google's R&D lab, Google Custom Search Engine, is pretty cool. Basically, Google has rolled out a service that lets you define the Web sites you want included in a search. So, for example, if you're really into food, you can use tags to create a personalized vertical tool that only searches food-related sites. And there's more: Google has also created a way to place this search widget on a Web site or blog so it can be offered to visitors with the same interests. While many of Google's new tools have been uninspiring or simply duds, DIY search is newsworthy because it's all about vertical search, which has been getting more attention as people look for tools to make search even more effective and productive. Now, Google DIY is interesting but I wonder if it's a sign of things to come from Google about its vertical search plans. For example, what if Google launched Google Travel Search for people interested in booking trips and learning more about the world around them. This would be a great way for Google to establish a huge foothold in the travel business if advertisers embraced it as an effective way to reach consumers. The same approach could be used for real estate, automobiles, consumer electronics, sports, etc. Maybe Google Custom Search Engine is a Trojan Horse that gets people turned on about vertical search. Once people like it, Google will simply roll out its own vertical search engines as a way to expand the market. For more, check out GigaOm and Matt Cutts, who provides a nice overview on Google DIY's features.