There's 2 that are the most popular- Statusnotifier which works in 3.0 but the actual app that lets you open settings won't work. But the notifier part will. And one called Notifier. That has been updated to work in 3.0
Does anyone know when Status Notifier for firmware 3.0(.1) will be out? At the moment, once installed, it keeps on crashing when the icon on the springboard is opened.