You need to open a message. There will be a icon showing something toaster-like with a down-arrow in it, a roughly octagonal surrounding an exlamation mark, a trash can, a pull-down button with a folder, and a pull-down button with a label.
Two of those icons make no sense at all (the toaster with down arrow for archive, and the octagon for spam). One makes no sense in the context of Gmail. It turns out that it is actually for manipulating tags just like the adjacent pull-down menu.
The trash can is pretty good though.
