Working late is a trip. I hung out after-hours at the pub next door, and now it's 4 am and I'm supposed to sleep? Biking home makes that hard.
The postmodernism thing. In brief, since I can't really speak very well now.
1) Postmodernism as architectural style. This is pretty straight forward it seems to me. There is a modernist school of architecture (FLW, I believe) and a strong, more or less clearly defined international set of rules, and the emergence of a "post" ought not to be surprising.
2) Keith Potter: Postmodernism as sampling. Potter, writing about minimalism, samples lightly from Foster, who samples from Jameson, to establish postmodernism pan-generically as characterized by quotation in a more or less esoteric manner. Questions like "Mahler?" and "Schubert?" are left open.
3) Jameson himself. For now, because it's 4 am, I'm skipping Foster (I've had too much Jameson for another Fosters). Aside from Potter's interest in quotation, Jameson is interested in the "decentered subject," which he borrows in part from Barthes. Spivak goes to town a bit on this, suggesting that the idea that the so-called postmodern subject--that is, you and I-- is decentered only in so far as the modern subject--your mom and dad--felt anxiety, etc. That is to say, that Jameson is renaming already cataloged phenomena in the interest of presenting a break or rupture where there is in fact only a repetition or continuation.
4) Lyotard. Lyotard, though again Spivak shows some useful flaws, is perhaps the best account so far. For him, postmodernism seems to be about the commodification (i'm done looking up spellings) of information. This is only possible through the development of digital technology, and is a clear difference between contemporary society and the fin-de-siecle anxiety typified by high modernism. The question looms: is it useful to talk about art in these terms?
Again, this is the short version.