Actually I understand what you are saying. I use my iPhone every day for various tasks. It has become one of the tools I use for every day life.Now, 5 months later, it's gotten really boring and there's not much it can really do.
It's when something happens that I appreciate my iPhone. For instance, the other day I needed to send some important e-mails out to various people. I needed to do it quickly. We take it for granted but the iPhone interface makes it easy to perform functions that are both clumsy and cumbersome on other phones.
I get the feeling that you may have not explored all of the stuff your iPhone can do. Try digging more into the functions and maybe download a few more apps to keep the fun alive. There is always something in the app store to liven up boring iPhone day.