Ellen Ripley's "Alien Stomper" Reeboks from were showcased in Aliens for a split second, were sold in limited quantities in 1987, and have been remade sporadically since then. Next month, Ripley's clodhoppers hit shelves once again (in Japan).
In the history of totally obscure product placement, the Alien Stompers might just take the cake. They had a couple blink-and-you'll-miss-them cameos in the movie and were on sale in ridiculously low numbers. In September, these Velcro-heavy sneakers (laces are so 21th century) will be on sale again in new colors for approximately $125. The only downside? It looks like they'll be available primarily in Japan.
If you manage to score a pair, please note that the sneakers are not acid-resistant. If you're looking for a corrosion-proof footgear, I'd recommend the Weyland-Yutani Alphadium Composite Party Loafers. I've had mine for years, and trust me, they've spared me from many a bout of xenomorph-related abashment.