Vanessa Fox has an excellent post documenting how to get them on your page. I went through the process as well. I have one pet peeve.
I went to add the information for the Search Engine Roundtable to my iGoogle page, as it says over here:
However, when I added it, it added all my sites under my login to my iGoogle page. I don't want all of them, just some of them. But you can change them by clicking on the arrow down. Here is a screen capture of what some of the sections look like:
Forum discussion at Google Groups.