Keep an eye on rei-outlet.com, they were still dumping last year's fleece a few weeks ago. Usually there's also another dump once inventory gets transferred fully out of their stores / warehouses and they figure out how much they really have to move. Last year the rough deal was 2007 Polartec 200 or 300 for $19.93 about this time of year. And the newer 2008 stuff coming in sure looked identical to me.

Like scafool says, end of winter is a good time to stock up on thermal underwear and march-april seems to be a good time to get a cheap rain jacket.