I have a dual monitor setup, my main monitor is a 22" running 1680 x 1050, and the secondary one is a 17" running 1280 x 1024. I don't know if I would go back to a single monitor on my home computer again. I find it very useful, but it does depend on what you do at home.
I use both monitors even for just answering email. I like having my mail program on the smaller screen, and my reply email on the larger screen, that way if I am answering questions, I still have the questions in front of me. I also work on books, and have to make changes, so my list of changes is on the smaller screen, while the main screen contains the books I'm working on.
Anyway, like the others have said, if your computer can handle it, try it first before getting rid of your extra monitor.