If you are having your own website or blog and it has its own google custom search engine, then you can add that in your iGoogle account where it will appear adjacent to the original google search bar. It will simplify the purpose where you need to search an item in your blog or website as well as google.
For those who are newer to iGoogle, iGoogle is a product or application provided by Google where you can have multiple options to browse. You can access the iGoogle with your Gmail account. Please refer to my article “Create your own customized home page with iGoogle“.
The question is why you should add that if you can search the items (including your own blog’s or website’s) in original google search on iGoogle. Your blog’s search engine will show the results only related to your blog, in fact Google original search on iGoogle will also show the results from your blog (if your blog is indexed) but that may be one page 1 or 2 or …. In that case you can have both the search engines on your iGoogle and can compare the results of an search item. This will let you know the keywords which you can put on your blog to improve the search result on original Google search.
Once you will put the keywords and tags properly on your blog or website, that will increase the traffic on your blog.
How to add the custom search console in iGoogle:
2) You should have a Gmail account with you and that account should be attached with the website or blog.
Go ahead with Google Custom search on iGoogle.