I have just found that Google developers have added another cool feature: Create a Custom Search Engine on the fly. You only need to specify the location of a blog or webpage and enter the keyword you are looking for. You’ll then get results from all the sites the webpage links to.
Try out the following searches (with Hausa Online as the starting page):
Of course, you can use this new feature for other searches, using your own websites as a starting point. I find this very helpful!