Safely Remove Hardware Disappear?

I have several USB devices, and I'm used to using the "safely remove hardware" icon in the taskbar before I unplug any of them. All of a sudden that icon has disappeared, and I see no way to "safely remove hardware". What do I do? Can I just unplug the device I want to remove anyway? Or do I need to reboot every time this happens?

Solution:
Click [Start]->[Run] and type:

RunDll32.exe shell32.dll,Control_RunDLL hotplug.dll

Press [Ok]
That will bring up the "Safely Remove Hardware" dialog: