for the past few months every so often I will get a notification in my notification bar that doesnt belong. its normally a star of some color and the desription in the pull down varies. It only shows up when I update my apps (not a certain app, that changes all the time) or when my battery is low. The description varies from "Get a new ring tone" or "youve just won an ipad" or "increase your battery life". When I click on it, it brings me to some wedsite that says appbott but it changes some times as well, this is what makes me think its a virus (I rarely click on it...but its the only way to get rid of it)
I have a virus scanner but it doesnt pick anything up. is this a virus? Can I reformat my phone to get rid of this?! any help would be appreciated.

It's one (or more) of your apps using push notification advertising. Removing the app that's causing will get rid of it. Some apps have an opt-out of push notifications in the settings of the app though. If you really need the app check it's options/settings to see if you can opt-out of notification ads. To find which app is doing it, there are scanners on the market that will find the app for you. Such as this one: http://www.androidpit.com/en/android/market/apps/app/com.lookout/Lookout-Security-Antivirus