This weekend, check out manmade ski jumps, old computers, and — in case you're not completely over Fake Steve Jobs — more, more, more Dan Lyons! All in this weekend's Valleywag Calendar.

• Plaxo, one of the OpenSocial members, shows off "the opening of the social Web" today from 4-6 p.m. at their offices in Mountain View. [Upcoming]
• The Vintage Computer Festival is this weekend at the Computer History Museum. If you're a supernerdy way-old-school videogamer, you can play Space War on an original PDP-1. That's the first videogame ever, on the first machine it was programmed for. [Vintage.org]
• More Dan Lyons! Tonight, he's reading Options at Books Inc in the Castro at 7:30 p.m. And by "reading Options," we actually mean "cracking jokes about Nick Denton and Robert Scoble." Lyons never actually reads from his book at these things. [Upcoming]
• Icerair, the build-a-ski-jump party in San Francisco, takes place at AT&T Park this weekend. [Icerair]

Contact information for this author is not available.