Alexa, the search engine best known for its toolbar and traffic-based services, is reported in both The Wall Street Journal and The Guardian to be planning to allow web developers and others in the industry to ask for customised searches, looking for images or music files, for example, during web crawls.

For instance, someone who wanted to build a podcasting search engine could use Alexa’s tools and computers to request specialized audio files that were newly available on the Web.

Alexa is owned by Amazon.com, and the tool will be offered as part of the Amazon web services. The platform launched in beta yesterday and has been greeted with a guarded enthusiasm by John Battelle in his Searchblog.

While Alexa is still small in terms of Google or Yahoo, I’d hope that this should help bring us user-friendly and focused products to help us get what we want when we go online. I’ll be interested to see what happens, and how the major search engine comanies might respond.