Do you Google? iGoogle is a customized page that you can add all sort of widgets or stuff to. You can have more than one page - each page is shown as a separate tab.
I have 1 tab called home. It has a section for Google Bookmarks (a cool way to access your favorite links no matter where you are), Gmail, Google Calendar, Local weather, and a To-do pad.
I have 2nd tab called news. It has, well, news. You can get CNN headlines, People, all sorts of stuff.
My 3rd tab is called Writing. This has all my writing tools. Thesaurus, Dictionary, Wikipedia, Unit Conversion (I'm Canadian and used to thinking in metric), Etymology, Acronyms, Grammar and Writing tips, Word of the Day, and a Map My Word visual dictionary / thesaurus.
There's a lot more - you can get lost in all the stuff that you can add to these pages and they are quick and easy to get. Google will even set up a page based on the title you give it but you can easily add, delete and move stuff around.
I find it incredibly useful. I'm mostly using the Thesaurus and Dictionary right now as I am in the final stages of editing my novel but I can't wait to start actively writing again so I can play with all my new toys.
Anyway, I hope you find it useful.