You can easily locate contact details for all of your representatives at VoteSmart.org They have a nice interface where you can enter your address and find out everybody who represents you at the federal, state, and local levels.
You can call your federal representatives and Senators by dialing the Capitol Switchboard. (I still remember the number!)
They can also give you email addresses.
But, there's a big question:
Why would you direct the same comments to state and federal representatives? They do completely different things.
The message you would communicate to your Congressman should be different than your Senator. Before contacting a representative of any type, you are well-advised to consider what they can actually do.
Let me explain.
Let's say that you are concerned about how the schools are being run. Your federal representatives are powerless to affect the school board. Indeed, about the only control that a Congressman has is the ability to affect funding for College loans. (Okay, if he calls the school board, he's got some influence because of his position - but no power.) I can't tell you the amount of mail your Congressman gets about things he has absolutely no influence over. The only response he can give you is "Talk to the right people." See this article in Lifehacker for dealing with local officials. You'll note their first piece of advice: Make sure you are hitting up the right person!
Let's say that you have a federal issue that you care about. The House and the Senate have to have similar but separate bills. Yes, you can write both of your senators the same note, but saying, "Please support HR-3285" (A House Bill) is completely non-sensical. Senators vote on bills in the Senate, Congressmen vote on bills in the house.
You state senators and state congressmen have their own legislative session dealing with state matters. Where a road goes, what the welfare in your state will be - these are the issues your state deals with. Foreign Policy? Defense? Treaties? that's the feds. The two don't overlap.
So, no. There is not a "one-stop" submit. (Okay, there isn't an official one, but there probably isn't a good one.) If you want to copy the text and email, knock yourself out. But you really should be asking yourself, why would I want to send the same anonymous rant to everyone in the first place?
Most likely, the only common message you'd have for each of them is nothing but spam.