brett Favre madness!

Even though it seems like he's been teasing his retirement for a decade now, it may be real this time. Brett has officially filed retirement papers with the NFL.

--Of course, those don't set it in stone . . . but there's a much stronger sign he's hanging it up. Sunday night, he started selling "Thanks for the memories" memorabilia on his website,

OfficialBrettFavre.com.