Friday night, I partied. The occasion: an office-warming party for two dot-com startups in San Francisco.

What reason would they have for celebrating an office? How about a fantastic SoMa location, bean-bag chairs in the conference room, and hardwood floors. The place even has history: it had been occupied by Yelp.

The party drew so many people that it was difficult to move. Most everybody in the crowd was an entrepreneur, a wanna-be entrepreneur, or a venture capitalist. Some were clearly taking advantage of the networking opportunity, but far more were taking advantage of…

…the open bar.

Yes, the good times are rolling again in spite of the shaky broader economy. I asked one of the founders about the logic of throwing a party — with an open bar, no less — after recently taking investment money. The reply? It’s remarkable what you can get away with when you’re cash flow positive. The sight of happy investors walking around with drinks in hand testified to the veracity of that statement.

More than the open bar, entrepreneurial crowd, and swank digs, the white board screamed “Startup!” On it, the company had a long list of items that they needed. Most were mundane necessities (markers, paper, and other office supplies), but only one was checked off: RockBand.

(recreation — my camera phone is horrible)

It felt like 1999, but with profit.