Quick Update:
First, thanks for the comments tarin - I'll make the attempt to write as many concise details as possible after a few more sits when I'm hopefully able to pick out more patterns. Is that state one of the immaterial jhanas or just deep 4th jhana?
Here's a few notes about my sit just now, though, and then below is a longer bit about some kundalini-type experiences going on:
-The past few sits I've seen the frame-by-frame flash by a few times. It's so fast though, am I to just note it like anything else or incline the mind in that direction?
In terms of the cycle of the sit:
-a single, small dot of bright light will appear around various spots a few times
-churning of the mindspace, mixing of vibrations
-sometimes one or several of the following occur: boredom, fear, indulgent sadness or a maudlin-type mindstate, anxiety, etc. when these thoughts come up, there is an obvious, immediate embodied feeling in the stomach of a rush of adrenaline or some type of intense fearful sensation.
-pain/nausea-like feeling in the sacral chakra for some time, like stomach is churning but worse
-eventually pain dwindles
-later will notice pain or tension in the throat
-quickening of the high-pitched mindsound, seems to fill the mind -- often it will "flood" the mind and it feels like the body tenses up to "force" it in...it's half intentional, half unintentional - make sense to anyone?
-frequency of vibrations continues to increase and "mix" (ie synchronize?)
-often around this time (but not exclusively) my posture will shift, with the spine relaxing and stooping a bit. I usually try to balance with letting it happen a bit but not too much
-eye flashing (lightening, camera-type flashes) then occurs
-around now, the painful thought-adrenaline rush is greatly diminished -- only notice some pressure in the stomach, not as much of the "chemical" sensation of anxiety or fear
-sometimes I'll feel warmth in the legs and/or please billowing, fire-like sensations all over the head
-hard to put, but it feels like the mindspace expands and dissolves parts of my body (the rest of my head, parts of my shoulder) - however, there's still the sense of a centerpoint
-after the flashes occur for sometime, there will occasionally be a few occurrences of the frame-by-frame (a few consecutive moments where it seems everything freezes temporarily)
in terms of technique:
-start with noting the breath and any thoughts and feelings that come up (thinking, fearing, hoping, desiring, etc. - sometimes more detailed depending on the speed of thought)
-when the flashing occurs will start to focus on intentions, desires for enlightenment, thoughts of progress, etc (I do this all the time, but the anticipation kicks off more thoughts around this period) and also feelings of comfort etc
-this last sit I really focused on the tension and stress the lines the perimeter of even the pleasant experiences -- this seemed to "progress" things some
-a lot of pieces of advice from DO start to come to mind and even make more sense (e.g. tarin's observation of how "reaching" of the mind, movement, etc. is only a quality of the mind...hopefully I got that right, but something along those lines really seems to make sense when I'm there)
Okay, so anyone who wants to weigh in on the above with tips, by all means

and thank you!
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Okay, the kundalini stuff for anyone who's interesting:
I had gotten sidetracked the past several sits with some kundalini openings (slowly creeping electric-fiery sparks moving up my spine during one sit) and some shaking/swaying/etc experiences that seem to come up toward the 3rd-4th vipassana jhana transition (I *think* it's toward the end of Re-Observation/Equanimity). It seems quite a DO folks have experience with this, so I'll track down those threads at some point.
The shaking is a weird thing (actually, only saying it sounds weird…it seems completely "normal" like any other impermanent phenomena or process of the mind), as it's something I can stop at any time, and actually when it happens my body is incredibly relaxed and not exerting any effort (or seems so). It really has seemed to help my body sort itself out a bit (lots of back/joint issues that are slowly recovering), but I think it's a divergent path from gaining stream entry, or at least a bit of a detour as it basically ends my meditation before I can get a solid footing in equanimity or wherever I've been ending up! I was also getting caught up by the experiences and becoming lost in the thoughts of progress/theorizing/fantasizing/etc. While they may be cathartic and "cleansing" I'd like to go ahead and get stream entry first!
Perhaps a useful thing to explore a little later on. Maybe I'll write up a more detailed post about it once I get settled after my move and so forth.
So anyway, I stumbled across the
"Bored in Equanimity waiting for first Path?" thread was incredibly helpful, as was
"I got lost, help me get back on track" for cluing me in on my own distractedness and slacking on investigation in respect to the kundalini experiences.
I think I'm going to start working on concentration for the first part of my sits, as recommended by a few in the first thread. I've done it a few times and it seems to help. I'll also be making some vows to postpone the "cleansing" shakes or whatever they are until Path, if possible

Unless something major happens in the next week, I may not be able to post a detailed update, or at least as often, until mid-next week after I'm (hopefully!) settled in Chicago (btw, this will probably be a separate post as well, but any good teachers or DO hardcore-dharma folks in that area?).
Thanks everyone!
-Chris