IMPRESSED AS I WAS BY the Getty Center and other pieces of "high" architecture in L.A., inevitably I was just as or more fascinated by the "flimsy buildings". Most buildings in Southern California are street-scale, designed at least partly for the benefit of passing car: sign as well as building.

The idea of this casual, less self-serious architecture appeals to me for several reasons. First of all, it allows for an end-run around that stiff and exclusive word "Architecture." You can reasonably substitute words such as "building" or "construction" or "decor" -- activities available to any creative person or handyman, rather than just those in the rarified guild of architects.

I think Banham's observation is apt, drawing a correlation between the "land covered only thinly with very flimsy buildings" and L.A.'s sense of freedom and creativity. In the older and highly built-up city of New York, "decor" and design tend to be something that most people indulge and experience mostly in private, in the individual spaces carved out within large and impersonal buildings -- office towers, apartment blocks, continuous rowhouses.

While in L.A., I thought a lot about the simple but profound act of altering your own environment: choosing a color to paint your house, or making a sign or awning for your store. In L.A., you have a feeling this is done with unusual enthusiasm. And the Fatburger in West Hollywood really does seem to glow with color like that -- it wasn't just a trick of the photograph.

Another appealing quality of roadside architecture is its direct language. After a few years of designing advertising, I've come to appreciate that using a direct, even blatant "pitch" can actually be a way to respect the consumer, by conveying the relevant point in the least possible time. When the goal is to communicate something to a totally uncaptive audience, which is free to continue driving or flipping through the magazine, as the case may be, you can't be precious or obscure.

Call it a case of less being more, but this "honesty" of form can be the result of sophisticated design thinking. Take the In-N-Out, in Westwood Village, designed by Kanner Architects in 1998. This is vernacular adapted into professional design -- high-brow Pop; the buildings shapes are derived from the cheekily-named burger chain's distinctive logo. It exemplifies what Robert Venturi called "the architecture of persuasion."

When I saw this facade in Pasadena, I thought, how ironic, this ornate terra-cotta showpiece fallen to the lowly role of car dealership. Looking it up on the Internet later on, however, I discovered that it had been originally built as a car dealership, for Packard (a marquee brand) in 1926. I forgot that in the early days, car dealerships were conceived to impress, like traditional bank lobbies.

It's rather charming, I think, that a car-dealer seeking respectability could turn to grand Spanish Baroque ornament, rather than, say, the Greco-Roman forms habitually adopted by large banks (and by the New York Stock Exchange, for that matter). It points to the diversity of formal -- i.e. visual and architectural -- languages that have long been present in L.A.

I liked the terra-cotta detailing on this branch of Louis's Trattoria in Pasadena. To me, noteworthy, but for L.A. actually unremarkable -- in that Spanish Colonial influence is everywhere. So are Meso-American motifs, such as in Frank Lloyd Wright's buildings; and Hispanic; and, to a lesser extent, Asian-derived forms such as post-and-beam construction; along with the European-derived forms, of course.

While it may be true that L.A.'s diverse cultures are kept apart by de facto segregation and by automobile usage, an extraordinary melding of influences is visible in the built environment. In New York, by contrast, an extremely diverse population interacts at close hand, by necessity; but the built environment has little trace of anything but European influence.

TopFuel Kawfee House in Hollywood -- a cool piece of car-culture homage.

I don't know what the "7702 SM Club" is, exactly -- I found out it's exact name from an online yellow pages -- but it has perhaps my favorite facade of all those I came across in L.A.. It's a strange contemporary reinterpretation of Southwestern motifs and hues, invitingly warm but also partly suggestive of an old jailhouse; and something you can hardly imagine seeing in any other city.

Call it aesthetic self-confidence or something, but L.A. seems to easily generate these strange native forms, and take pleasure in being a style unto itself.