I have this Twitter search saved in my Google Reader. It works OK. One recent tweet by DismalTrader linked to an old Stata Journal article about demand estimation, saved on Scribd. This reminded me that The Stata Journal has a three-year moving wall: anything older than three years prior to the latest issue is available free, in beautiful PDF. The article I'm talking about, for example, is here. One of these days I'll make time to feature at least one such article every week. Until then, bookmark the thing and go poke around. There's a lot of good stuff in those back issues.