I don't think that's exactly the same comparison. Orbitz, to me, seems much more corporate and doesn't have the same connection with the developer and startup community that these do. That's not to say Orbitz isn't worthy of attention, merely they don't shove it in our faces like 37signals ;)
No, but it's a good example of a startup that had a solid foundation, good management team, and ramped up into a successful IPO without a 9-figure G round. A lot of other startups have sprung from that event.
It's a shame that a lot of people have forgotten that and mention Groupon and GrubHub like they're the one-and-only models for a startup scene in this city.
Every time someone says this, the neck-hairs of every Orbitz employee (current and former) stand up on end and twitch a little.