Mike Sandison claims that the album has a concept (that concept being a guy who is at a campfire and is tripping on acid), but I like to think that the album traces the path of said trip. Though a bunch of the song titles are just hallucinatory oddness, some actually relate to the plot, so those are the ones I will put here.
Into The Rainbow Vein - taking the acid and starting to get in the psychedelic zone.
A Moment of Clarity - according to Wikipedia, some LSD users experience a lucid sensation and feel greater insight into themselves. This is happening to the protagonist.
'84 Pontiac Dream - the protagonist is likely to be in his early 20s (unless I have my acid-taking demographic wrong - and I probably do), meaning that at the time the album was released (2005), he would have been born in the early 80s. This syncs up with the year the car was released, so this song is a representation of a psychedelic experience that involved said car, likely that of his parents. Alternately, it's a reference to KITT from Knight Rider, which is an '84 Trans Am.
Oscar See Through Red Eye - it's been several hours by now, and the protagonist is getting tired (represented by the especially drawn-out synth tones, but it's kind of hard to go to sleep on acid (as represented by the at-times frenetic beats.) Also, his name is revealed: Oscar.
Ataronchronon - the title refers to a particular tribe of Huron Indians, which may mean that he's in the Midwestern United States or - wait for it - Canada. Quite possibly one of the sneakiest band name drops ever.
Hey Saturday Sun - it's really been awhile; in fact, over the last two songs, a whole night passed. Mr. Sandison claims that acid messes with your perception of time like that. It was Friday night, and now it's Saturday morning.
Constants Are Changing - this is when things he assumes are constant truths about the universe, even on acid, start changing. And you know what that means: The trip's turned bad.
Slow This Bird Down - metaphor-speak for "Get me off this acid!" However, the song's pretty calm; it's more of a general unease than an Oh Crap. Alternately, this isn't a metaphor, and he's hallucinating riding a giant bird.
Farewell Fire - The trip's over, everything's normal again, it's time to go home.