I use Firefox as my browser now and checked out the add-ons to the program. Many of you might already be aware of answers.com but I'd like to bring it to the attention of those that aren't.
It's a very quick download. It allows you to click on a word while holding down the Alt key and a pop-up window gives you the definition, pronunciation, origin, uses of the word in sentences, multiple encyclopedic references, quotes using the word...you name it. If you don't know how to spell the word, type in how you think it's spelled and it will give you alternatives to your spelling.
This is one of the most amazing tools I've ever seen on the internet, and it's free.
Thanks to all of you who turned me on to Firefox in the first place. Awesome browser.